ChatGPT for Tinnitus Information and Support: Response Accuracy and Retest after Three and Six Months

Testing of ChatGPT has recently been performed over a diverse range of topics. However, most of these assessments have been based on broad domains of knowledge. Here, we test ChatGPT's knowledge of tinnitus, an important but specialized aspect of audiology and otolaryngology. Testing involved evaluating ChatGPT's answers to a defined set of 10 questions on tinnitus. Furthermore, given the technology is advancing quickly, we re-evaluated the responses to the same 10 questions 3 and 6 months later. The accuracy of the responses was rated by 6 experts (the authors) using a Likert scale ranging from 1 to 5. Most of ChatGPT's responses were rated as satisfactory or better. However, we did detect a few instances where the responses were not accurate and might be considered somewhat misleading. Over the first 3 months, the ratings generally improved, but there was no more significant improvement at 6 months. In our judgment, ChatGPT provided unexpectedly good responses, given that the questions were quite specific. Although no potentially harmful errors were identified, some mistakes could be seen as somewhat misleading. ChatGPT shows great potential if further developed by experts in specific areas, but for now, it is not yet ready for serious application.

Comparison of the audiological knowledge of three chatbots - ChatGPT, Bing Chat, and Bard

INTRODUCTION

The purpose of this study was to evaluate three chatbots - OpenAI ChatGPT, Microsoft Bing Chat (currently Copilot), and Google Bard (currently Gemini) - in terms of their responses to a defined set of audiological questions.

METHODS

Each chatbot was presented with the same 10 questions. The authors rated the responses on a Likert scale ranging from 1 to 5. Additional features, such as the number of inaccuracies or errors and the provision of references, were also examined.

RESULTS

Most responses given by all three chatbots were rated as satisfactory or better. However all chatbots generated at least a few errors or inaccuracies. ChatGPT achieved the highest overall score, while Bard was the worst. Bard was also the only chatbot unable to provide a response to one of the questions. ChatGPT was the only chatbot that did not provide information about its sources.

CONCLUSIONS

Chatbots are an intriguing tool that can be used to access basic information in a specialized area like audiology. Nevertheless, one needs to be careful, as correct information is not infrequently mixed in with errors that are hard to pick up unless the user is well versed in the field.

Magnitude of medial olivocochlear reflex assayed by tone-burst-evoked otoacoustic emissions: reliability and comparison with click-evoked emissions

OBJECTIVE

The purpose of this pilot study was to evaluate the magnitude of the medial olivocochlear reflex (MOCR) estimated by the reduction in tone-burst evoked otoacoustic emissions (TBOAEs) measured at three levels and at three frequencies in response to fixed contralateral white noise. Results were compared with commonly used click-evoked otoacoustic emissions (CEOAEs).

DESIGN

TBOAEs and CEOAEs, with and without contralateral 60 dB SPL white noise, were measured in response to stimulation at 55, 65, and 75 dB peSPL. In each subject, the set of measurements was performed twice. Of particular interest were the MOCR and its repeatability.

STUDY SAMPLE

15 normally hearing persons (13 women, average age 32.3 years, SD = 8.1).

RESULTS

For both CEOAE and TBOAEs, the reliability of the MOCR was much better for broadband measurements than for half-octave-band filtered estimates. At the same time, the reliability of MOCR in half-octave bands was higher for TBOAEs than for CEOAEs, especially at 2 and 4 kHz.

CONCLUSIONS

For general applications where broadband MOCR is of interest, the highest magnitude and reliability is provided by CEOAEs. However, TBOAEs may be better if a particular frequency band is of interest.

Effectiveness of transcutaneous vagus nerve stimulation for the treatment of tinnitus: an interventional prospective controlled study

OBJECTIVES

The aim of this interventional non-randomised prospective controlled study was to assess the effectiveness of transcutaneous vagus nerve stimulation (tVNS) in human subjects with tinnitus.

DESIGN

The ParasymTM tVNS device was paired with an auditory stimulation. Treatment and observations were conducted over 12 weeks. Audiological evaluation was performed. Responses from a set of questionnaires and quantitative electroencephalography (qEEG) before and after treatment were collected. Voice measurements were done to assess possible side-effects of tVNS.

STUDY SAMPLE

The study involved 29 adults who had chronic tinnitus (15 patients who underwent tVNS paired with sounds and a control group of 14 patients who did not).

RESULTS

In general, subjective and objective measurements of tinnitus showed no improvement in the study group compared to the controls, although certain parameters as gauged by the questionnaires did statistically improve. The loudness and frequency of tinnitus remained the same in both groups. For the qEEG, activity in the theta band increased significantly in the study group compared to the control group.

CONCLUSIONS

The tVNS was not effective in reducing tinnitus symptoms in our study group. However, changes in the theta band suggest there might be cortical effects that might, with sustained treatment, lead to improvements.

Effect of the COVID-19 Pandemic on Resting-State Brain Activity in Individuals with Tinnitus

This study looked at the possible effect of the COVID-19 pandemic on individuals who came to our clinic seeking relief from tinnitus. The performance of the subjects during the COVID-19 pandemic was compared with similar individuals who came to our clinic before the pandemic began. The study involved 50 adults with chronic tinnitus, made up of a study group (24 subjects tested during the COVID-19 pandemic of 2020-2021) and a control group before the pandemic began (26 subjects tested from 2013 to 2017). None of the 24 reported having contracted COVID-19. Data collection involved the Tinnitus Handicap Inventory (THI) questionnaire, audiological tests, and quantitative electroencephalography (qEEG). In terms of THI scores, there were no statistically significant differences between the two groups. However, with regard to qEEG, some changes were observed, with significant decreases in alpha and beta band activity in the study group compared to the control group, particularly over the auditory cortex. We conclude that COVID-19 did not have a discernible impact on the general well-being of individuals with tinnitus. However, it did appear to alter brain activity, specifically in the alpha and beta bands over the auditory cortex, and these reults warrant further investigation.

Satisfaction with life in a sample of prelingually deaf cochlear implant users with a good command of spoken Polish as the primary language

INTRODUCTION

This study investigated the level of satisfaction with life (SWL) in a group of cochlear implant (CI) users who had been prelingually deaf but were orally educated. They had received one or two CIs (as a child, adolescent, or adult) and were highly competent Polish speakers. This study looked at three factors that may affect SWL - psychosocial, deafness/hearing and communication related, and sociodemographic.

METHODS

The participants were prelingually deaf CI users who had learned highly competent spoken Polish as their primary language. They had been educated in mainstream or integrated schools (not schools for the deaf), and had no other disability or severe illness. Measurements were done with 5 questionnaires: the Satisfaction With Life Scale (SWLS), the I-Others Questionnaire, the Patient Health Questionnaire (PHQ-9), the Deaf Identity Development Scale (DIDS), and the Nijmegen Cochlear Implant Questionnaire (NCIQ).

RESULTS

The SWL level of the group was similar to that of the standard Polish population. SWL was positively related to positive self-perception, acceptance of oneself as a deaf person, and to perceiving the benefits of having a CI (as measured by three NCIQ domains: self-esteem, activity limitations, and social interactions). On the other hand, negative self-perception, marginal deaf identity, and depressive symptoms were negatively related to SWL. There was no relationship between SWL and knowledge of sign language. Lower depressive symptoms and greater hearing loss were both significant predictors of SWL, although those who used two CIs generally had a lower SWL.

CONCLUSIONS

Prelingually deaf CI users with low SWL require psychological support in many spheres, including working through problems of deaf identity, self-acceptance, and depression. Additional research should involve diverse DHH CI users, including those with limited spoken Polish competency or sign language skills, as well as members of the Polish Deaf community.

Cooling the Cochlea: Slowing Down Metabolism May Be a Way of Protecting Hearing from Surgical Trauma

Background and Objectives: This narrative review of the literature explores the effect of body temperature on hearing. In particular, its focus is on extended high frequency (EHF) hearing-the range beyond the standard audiometric limit of 8 kHz. Such high frequencies are the first to be affected by noise-induced hearing loss, and so monitoring them can provide an early warning sign of incipient damage. Materials and Methods: This review builds on a personal literature database of 216 references covering the general topic of EHF hearing; the procedure was to then identify papers related to whole-body or cochlear cooling. A starting point was the paper by Munjal et al. who in 2013 reported changes of up to 15-30 dB in the EHF thresholds of subjects who had undergone cardiopulmonary bypass (CBP) surgery, which typically involves mild to moderate hypothermia-cooling of the blood-to reduce cellular oxygen demand and minimise tissue damage. Results: Reviewing the surrounding literature, we find that although CBP surgery by itself can impair hearing thresholds, lower body and cochlear temperatures in general provide neuroprotective effects. A connection between hearing loss and CBP surgery has been periodically documented, but the mechanism behind it has yet to be conclusively identified. Conclusions: The observations reviewed here tend to confirm the otoprotective effects of cooling. We consider that the high sensitivity of EHF thresholds to temperature is a major factor that has not been sufficiently recognised, although it has important implications for otological research and practice. Two important inferences are that, first, monitoring EHF thresholds might have considerable value in audiology, and, second, that lowering temperature of the cochlea during cochlear implantation might provide substantially better hearing preservation, as some researchers have already suggested.

Visual attention does not affect the reliability of otoacoustic emission or medial olivocochlear reflex

This study investigated whether visual attention affects the reliability (i.e., repeatability) of transiently evoked otoacoustic emission (TEOAE) magnitudes or of medial olivocochlear reflex (MOCR) estimates. TEOAEs were measured during three visual attentional conditions: control (subject were seated with eyes closed); passive (subjects looked at a pattern of squares on a computer screen); and active (subjects silently counted an occasionally inverted pattern). To estimate reliability, the whole recording session was repeated the next day. The results showed that visual attention does not significantly affect TEOAE or MOCR magnitudes-or their reliability. It is therefore possible to employ visual stimuli (e.g., watching a silent movie) during TEOAE experiments, a procedure sometimes used during testing to prevent subjects from falling asleep or to keep children still and quiet.

Medial olivocochlear reflex reliability: The effects of averaging and presence of synchronized spontaneous otoacoustic emissions

The medial olivocochlear reflex (MOCR), usually assessed by the inhibition of transiently evoked otoacoustic emissions (TEOAEs) with contralateral noise, is a very small effect. In understanding the origin of the MOCR, it is crucial to obtain data of the highest accuracy, i.e., with a high signal-to-noise ratio (SNR), which in turn largely depends on the number of signal averages. This study investigates how the reliability of MOCR measures is affected by the number of averages. At the same time, the effect of the presence of synchronized spontaneous otoacoustic emissions (SSOAEs) is taken into account, as it is known that this factor significantly affects TEOAE amplitudes and SNRs. Each recording session consisted of two series of four measurements, allowing comparison of MOCR magnitude based on 250, 500, 750, and 1000 averages. Reliability was based on comparing the two series. The results show that, for a good quality MOCR measure (i.e., intraclass correlation above 0.9), the required number of averages is at least double that obtainable from a standard TEOAE test (i.e., 500 compared to 250). Ears without SSOAEs needed a higher number of averages to reach a correlation of 0.9 than ears with SSOAEs.

Fluctuations of Otoacoustic Emissions and Medial Olivocochlear Reflexes: Tracking One Subject over a Year

The purpose of the study was to measure the variability of transiently evoked otoacoustic emissions (TEOAEs) and the medial olivocochlear reflex (MOCR) over a long period of time in one person. TEOAEs with and without contralateral acoustic stimulation (CAS) by white noise were measured, from which MOCR strength could be derived as either a dB or % change. In this longitudinal case study, measurements were performed on the right and left ears of a young, normally hearing adult female once a week for 1 year. The results showed that TEOAE level and MOCR strength fluctuated over the year but tended to remain close to a baseline level, with standard deviations of around 0.5 dB and 0.05 dB, respectively. The TEOAE latencies at frequencies from 1 to 4 kHz were relatively stable, with maximum changes ranging from 0.5 ms for the 1 kHz band to 0.08 ms for the 4 kHz band. TEOAE levels and MOCR strengths were strongly and negatively correlated, meaning that the higher the TEOAE level, the lower the MOCR. Additionally, comparison of fluctuations between the ears revealed positive correlation, i.e., the higher the TEOAE level or MOCR in one ear, the higher in the second ear.

Self-perceived stress and the personality of mothers of children with central auditory processing disorders - Differences from mothers of typically developing children

PURPOSE

To investigate the relationship between self-perceived global stress and the personality traits of mothers of children with central auditory processing disorders (APD), and make a comparison with mothers of typically developing (TD) children.

DESIGN AND METHODS

A cross-sectional study using two questionnaires - the Perceived Stress Scale (PSS-10) and the Short Big Five Markers (IPIP-BFM-20) - to assess five personality dimensions: extraversion, agreeableness, conscientiousness, emotional stability, and intellect/imagination. The study material included 187 mothers, of whom 108 were mothers of children with APD. The average age of the children with APD was 10 years.

RESULTS

The average level of global stress was similar in mothers of children with APD and mothers of TD children. Mothers of APD children had significantly lower scores for personality dimensions such as: emotional stability, conscientiousness, and intellect/imagination. Increased perceived stress level in mothers of children with APD was inversely correlated with extraversion, conscientiousness, and emotional stability. However, for both groups of mothers, the only significant predictor of global stress level was emotional stability.

CONCLUSION

Mothers of children with APD, despite having similar global stress levels to other mothers, were different in terms of three personality dimensions, and these, especially lowered emotional stability, may play a negative role in coping with global self-perceived stress.

PRACTICE IMPLICATIONS

The results of this study might be helpful in parental support interventions, including psychological therapy and counselling, and also in parental implementation interventions aimed at mothers of children with APD, especially those mothers who have high global stress and/or low emotional stability.

Ultra-High Frequency Distortion Product Otoacoustic Emissions for Detection of Hearing Loss and Tinnitus

Several studies have suggested that distortion product otoacoustic emissions (DPOAEs) may be an early marker not only of hearing loss (HL) but also of tinnitus. The purpose of this study was to investigate whether DPOAEs measured up to 16 kHz are affected by the presence of tinnitus. Pure tone thresholds and DPOAEs were measured in two groups: 55 patients with tinnitus and 63 subjects without tinnitus. The subjects were divided into three groups according to their audiometric results-better than 25 dB HL at all tested frequencies from 0.125 to 16 kHz, better than 25 dB up to 8 kHz, and hearing impaired. Receiver operator characteristics (ROCs) were used to test whether DPOAEs could differentiate between normal hearing, hearing loss, and tinnitus. Comparison of tinnitus subjects with the control group, matched accurately according to thresholds, did not yield any significant difference in DPOAEs. However, in both these groups hearing loss was accompanied by a decrease in DPOAEs, specifically, at 2-6 kHz and 16 kHz. The results suggest that any decrease in DPOAEs seems to be related only to hearing loss and there is no additional effect from tinnitus.

Diagnostic utility of genetic testing in restrictive cardiomyopathy a single refferal centre experience

Introduction

Restrictive cardiomyopathy (RCM) is considered to have a genetic background in approximately 50–60% of patients (pts) [1,2,3].

Purpose

The aim of the study was to assess the frequency of pathogenic gene variants in Polish patients with RCM.

Methods

Restrictive cardiomyopathy was diagnosed by transthoracic echocardiography. The analysis included all consecutive unrelated pts with RCM admitted to the cardiology department from January 2015 to December 2016. Light-chain (AL) amyloidosis was diagnosed using tissue biopsy, concentration of serum free light chains and bone marrow biopsy. A genetic test was offered to every patient without AL amyloidosis. In 4 pts coding regions of TTR or GLA genes were screened by Sanger sequencing. Next Generation Sequencing (NGS) was performed: a panel covering coding regions of >4800 disease-associated genes in 18 pts and Whole Exome Sequencing (WES) in 2 pts. Classification of rare variants was made according to ACMG criteria [4].

Results

Forty-four pts were enrolled. Eighteen pts were diagnosed with AL amyloidosis. One patient was diagnosed with histologically-proven myocarditis and one patient with transthyretin (ATTR) amyloidosis declined genetic test. The other 24 pts (median age 48 yrs, 6 males) underwent genetic testing, their median values (interquartile ranges) of the following parameters were: NT-proBNP, 2508 (995–5895) pg/mL; hs-TnT, 25 (18–46) ng/L; E/A ratio, 2.5 (1.8–4.5); E wave deceleration time, 135 (98–167) ms; E/e' ratio, 16 (12–19); left ventricular (LV) posterior wall, 13 (12–14.5) mm; interventricular septum, 14 (13–17) mm and LV end-diastolic dimension, 48 (43–49) mm. Pathogenic or likely pathogenic variants were detected in 16 probands: 5 in MYH7 gene, 3 in TNNI3 gene, 2 in MYBPC3 gene, 1 in BAG3 gene, 1 in PRAKG2 gene, 2 in GLA gene and 2 in TTR gene.

Conclusions

Genetic testing is justified in every patient with RCM, in whom AL amyloidosis is excluded. The molecular diagnosis in RCM may result in causal treatment of Anderson-Fabry disease and ATTR amyloidosis or improve disease management in other types of RCM. MYH7 gene is the most common causative gene in Polish patients with RCM.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Cardiology

Posttraumatic Growth in Postlingually Deaf Patients With Cochlear Implants: The Effect of Stress-Coping Strategies, Sociodemographics, and Deafness-Related Factors

The aim of this study was to assess whether cochlear implant (CI) users who had been postlingually deaf developed a more positive outlook on life—the so-called posttraumatic growth (PTG)—as a result of their disability and to examine how PTG related to their stress-coping strategies and personal circumstances. The study group consisted of 119 postlingually deaf CI users. The participants were asked to anonymously fill in several questionnaires: the Post-Traumatic Growth Inventory (PTGI), Coping Orientations to Problems Experienced (Brief COPE), and a form asking for personal details and factors related to their deafness and CI use. The PTG of postlingually deaf CI users was similar to that found in people with other severe health problems. The time that had elapsed since the hearing was lost and the time from receiving a CI were positively correlated with PTG. The level of PTG was correlated with the particular coping strategies used and differed between men and women. We found that the development of PTG could emerge from both approach-oriented coping strategies (e.g., active coping and planning) and avoidance-oriented coping strategies (e.g., denial, self-distraction, and self-blame). Paradoxically, the avoidance strategies could play a positive role in the development of PTG. This reinforces the idea, previously raised in the PTG literature, that such strategies exert a defensive and protective function—an “illusory” side of PTG—which operates together with the positive constructive side, and both help develop the sense of well-being of a person.

Does the Presence of Spontaneous Components Affect the Reliability of Contralateral Suppression of Evoked Otoacoustic Emissions?

OBJECTIVES

The function of the medial olivocochlear system can be evaluated by measuring the suppression of otoacoustic emissions (OAEs) by contralateral stimulation. One of the obstacles preventing the clinical use of the OAE suppression is that it has considerable variability across subjects. One feature that tends to differentiate subjects is the presence or absence of spontaneous OAEs (SOAEs). The purpose of the present study was to investigate the reliability of contralateral suppression of transiently evoked OAEs (TEOAEs) measured using a commercial device in ears with and without SOAEs.

DESIGN

OAEs were recorded in a group of 60 women with normal hearing. TEOAEs were recorded with a linear protocol (identical stimuli), a constant stimulus level of 65 dB peSPL, and contralateral broadband noise (60 dB SPL) as a suppressor. Each recording session consisted of three measurements: the first two were made consecutively without taking out the probe (the "no refit" condition); the third measurement was made after taking out and refitting the probe (a "refit" condition). Global (for the whole signal) and half-octave band values of TEOAE response levels, signal-to-noise ratios (SNRs), raw dB TEOAE suppression, and normalized TEOAE suppression, and latency were investigated. Each subject was tested for the presence of SOAEs using the synchronized SOAE (SSOAE) technique. Reliability was evaluated by calculating the intraclass correlation coefficient, standard error of measurement (SEM) and minimum detectable change.

RESULTS

The TEOAE suppression was higher in ears with SSOAEs in terms of normalized percentages. However, when calculated in terms of decibels, the effect was not significant. The reliability of the TEOAE suppression as assessed by SEM was similar for ears with and without SSOAEs. The SEM for the whole dataset (with and without SSOAEs) was 0.08 dB for the no-refit condition and 0.13 dB for the refit condition (equivalent to 1.6% and 2.2%, respectively). SEMs were higher for half-octave bands than for global values. TEOAE SNRs were higher in ears with SSOAEs.

CONCLUSIONS

The effect of SSOAEs on reliability of the TEOAE suppression remains complicated. On the one hand, we found that higher SNRs generally provide lower variability of calculated suppressions, and that the presence of SSOAEs favors high SNRs. On the other hand, reliability estimates were not much different between ears with and without SSOAEs. Therefore, in a clinical setting, the presence of SOAEs does not seem to have an effect on suppression measures, at least when testing involves measuring global or half-octave band response levels.

Comparison of tympanometry results for probe tones of 226 Hz and 1000 Hz in newborns

INTRODUCTION

Impedance audiometry is a routine test for diagnosing hearing disorders in children. Typically, tympanometry uses a 220 or 226 Hz probe tone. However, using a 1000 Hz test tone is becoming increasingly popular, particularly in newborns, since it enables one to assess individual components of the ear's admittance.

AIM

This study compares tympanograms for test frequencies of 226 Hz and 1000 Hz in newborns and evaluate the rate of occurrence of each type of tympanogram for both frequencies.

MATERIAL AND METHOD

The study material was 53 newborns. All newborns underwent middle ear susceptibility testing at two measurement frequencies: 226 Hz and 1000 Hz. The parameters obtained with both frequencies were compared, and the utility of the 1000 Hz test frequency for middle ear diagnostics in newborns was evaluated.

RESULTS

The results show that tympanograms obtained from the same ear using different test frequencies are significantly different. The 1000 Hz tone produced a higher rate of type B tympanograms (flat).

CONCLUSIONS

Tympanometry curves for 226 Hz and 1000 Hz are different, and in newborns the 1000 Hz test tone revealed a higher rate of middle ear pathology. However, further studies are required to verify that 1000 Hz tympanometry is a high-sensitivity diagnostic method for middle ear problems in newborns.

Muscles in and around the ear as the source of "physiological noise" during auditory selective attention: A review and novel synthesis

The sensitivity of the auditory system is regulated via two major efferent pathways: the medial olivocochlear system that connects to the outer hair cells, and by the middle ear muscles-the tensor tympani and stapedius. The role of the former system in suppressing otoacoustic emissions has been extensively studied, but that of the complementary network has not. In studies of selective attention, decreases in otoacoustic emissions from contralateral stimulation have been ascribed to the medial olivocochlear system, but the acknowledged problem is that the results can be confounded by parallel muscle activity. Here, the potential role of the muscle system is examined through a wide but not exhaustive review of the selective attention literature, and the unifying hypothesis is made that the prominent "physiological noise" detected in such experiments, which is reduced during attention, is the sound produced by the muscles in proximity to the ear-including the middle ear muscles. All muscles produce low-frequency sound during contraction, but the implications for selective attention experiments-in which muscles near the ear are likely to be active-have not been adequately considered. This review and synthesis suggests that selective attention may reduce physiological noise in the ear canal by reducing the activity of muscles close to the ear. Indeed, such an experiment has already been done, but the significance of its findings have not been widely appreciated. Further sets of experiments are needed in this area.

No Change in Medial Olivocochlear Efferent Activity during an Auditory or Visual Task: Dual Evidence from Otoacoustic Emissions and Event-Related Potentials

The medial olivocochlear (MOC) system is thought to be responsible for modulation of peripheral hearing through descending (efferent) pathways. This study investigated the connection between peripheral hearing function and conscious attention during two different modality tasks, auditory and visual. Peripheral hearing function was evaluated by analyzing the amount of suppression of otoacoustic emissions (OAEs) by contralateral acoustic stimulation (CAS), a well-known effect of the MOC. Simultaneously, attention was evaluated by event-related potentials (ERPs). Although the ERPs showed clear differences in processing of auditory and visual tasks, there were no differences in the levels of OAE suppression. We also analyzed OAEs for the highest magnitude resonant mode signal detected by the matching pursuit method, but again did not find a significant effect of task, and no difference in noise level or number of rejected trials. However, for auditory tasks, the amplitude of the P3 cognitive wave negatively correlated with the level of OAE suppression. We conclude that there seems to be no change in MOC function when performing different modality tasks, although the cortex still remains able to modulate some aspects of MOC activity.

Reliability of contralateral suppression of otoacoustic emissions in children

OBJECTIVE

The purpose of the study was to determine the reliability in children of the medial olivocochlear reflex when measured as decibels of suppression of transiently evoked otoacoustic emissions (TEOAEs) by contralateral acoustic stimulation (CAS).

DESIGN

TEOAEs with and without CAS (white noise) were measured. In each subject, measurements were performed twice. Of particular interest was the suppression of TEOAEs by CAS and its reliability. Reliability was evaluated by calculating the standard error of measurement (SEM) and minimum detectable change (MDC).

STUDY SAMPLE

Fifty-one normally hearing girls aged 3-6 years.

RESULTS

The average global TEOAE suppression was around 0.6 dB. The highest reliability was for global values, with SEM of 0.2 dB and MDC of ±0.55 dB for the standard 2.5-20 ms recording window and slightly higher values for an 8-18 ms window. The worst reliability in the studied group was for the 1 kHz half-octave frequency band. Additionally, ears without spontaneous otoacoustic emissions had higher suppression levels than those with, but they also had lower signal-to-noise ratios, which may limit their clinical utility.

CONCLUSIONS

The current study shows that, under the studied paradigm, TEOAE suppression does not have satisfactory reliability since MDC was similar to the level of suppression.

Contralateral suppression of otoacoustic emissions in pre-school children

BACKGROUND

Contralateral suppression of otoacoustic emissions (OAEs) may serve as an index of the medial olivocochlear (MOC) reflex. To date, this index has been studied in various populations but never in pre-school children. The purpose of this study was to fill this gap and describe how the MOC reflex affects the properties of transiently evoked OAEs (TEOAEs) in this age group. In addition, the influence of the presence of spontaneous OAEs (SOAEs) in the studied ear on the suppression of TEOAEs was also investigated.

METHODS

TEOAEs with and without contralateral acoustic stimulation (CAS) by white noise were measured in 126 normally hearing pre-school children aged 3-6 years. The values of response levels, suppression by CAS, and signal-to-noise ratios (SNRs) of TEOAEs were investigated for the whole signal (global) and for half-octave frequency bands from 1 to 4 kHz. Only ears with SNR >6 dB were used in the analyses. SOAEs were acquired using the so-called synchronized SOAEs (SSOAEs) technique.

RESULTS

Ears with SSOAEs had higher response levels and SNRs than ears without SSOAEs, and suppression was lower (0.58 dB compared to 0.85 dB). Only 22% of all studied ears had an SNR >20 dB, a level recommended in some studies for measuring suppression. There were no significant effects of age or gender on TEOAE suppression.

CONCLUSIONS

Suppression levels for pre-school children did not differ appreciably from those of adults measured under similar conditions in other studies. Taken together with no effect of age in the data studied here, it seems that there is no effect of age on TEOAE suppression. However, we did find that the presence of SSOAEs had an effect on TEOAE suppression, a finding which has not been reported in earlier studies on different populations. We suggest that the presence of SSOAEs might be a crucial factor related to MOC function.

Self-esteem in the deaf who have become cochlear implant users as adults

Objective

Self-esteem is a good predictor of mental health and is crucial for well-being and psychological functioning. It is especially important in situations where there are potential mental health problems, such as in people suffering from hearing loss or total deafness. This study aims to gauge the level of self-esteem in adults with hearing problems, in particular those who, in adulthood, had received a cochlear implant (CI). The subjects had different onset (pre-lingual/post-lingual) and amount (deafness/partial deafness) of hearing loss, and their current level of self-esteem was compared to that of the general population. The association of self-esteem with other deafness-related variables (e.g. satisfaction with their CI or whether they also used a hearing aid) and sociodemographic factors was also investigated.

Methods

Data were obtained from questionnaires mailed to patients who, when adult, had received a CI. The subjects were divided into four subgroups: subjects with pre-lingual deafness, post-lingual deafness, pre-lingual partial deafness, and post-lingual partial deafness. To evaluate their self-esteem, the Rosenberg Self-Esteem Scale (RSES) was used. For data on sociodemographic status and information related to deafness and CI, we used our own Information Inquiry form. For statistical analysis of the results, we compared means (t-test, ANOVA), investigated correlations, and applied linear regression.

Results

The self-esteem of deaf and partially deaf CI users was significantly lower than in the general population, especially for post-lingually deafened subjects. The only factor related to deafness and CIs that explained self-esteem was self-rated satisfaction with the CI–meaning that higher satisfaction was associated with higher self-esteem. The major sociodemographic factor that explained self-esteem was marital/partnership status (being in a relationship was helpful). Also men had higher self-esteem than women. Those with higher levels of education, and those working or studying, had higher self-esteem than those who did not. RSES was found to have a single-factor structure.

Conclusion

Deafness and partial deafness appear to be risk factors for lower self-esteem, a finding that rehabilitation, medical, educational, and employment communities should be made aware of. Medical intervention in the form of a CI supplies the person with improved hearing, but it is not a panacea: their self-esteem is still vulnerable, and reinforcement of self-esteem is an aspect that professionals should focus on. Psychological, psycho-educational, and psychotherapeutic interventions have important roles to play for CI recipients.

Otoacoustic emissions from ears with spontaneous activity behave differently to those without: Stronger responses to tone bursts as well as to clicks

It has been reported that both click-evoked otoacoustic emissions (CEOAEs) and distortion product otoacoustic emissions (DPOAEs) have higher amplitudes in ears that possess spontaneous otoacoustic emissions (SOAEs). The general aim of the present study was to investigate whether the presence of spontaneous activity in the cochlea affected tone-burst evoked otoacoustic emissions (TBOAEs). As a benchmark, the study also measured growth functions of CEOAEs. Spontaneous activity in the cochlea was measured by the level of synchronized spontaneous otoacoustic emissions (SSOAEs), an emission evoked by a click but closely related to spontaneous otoacoustic emissions (SOAEs, which are detectable without any stimulus). Measurements were made on a group of 15 adults whose ears were categorized as either having recordable SSOAEs or no SSOAEs. In each ear, CEOAEs and TBOAEs were registered at frequencies of 0.5, 1, 2, and 4 kHz, and input/output functions were measured at 40, 50, 60, 70, and 80 dB SPL. Global and half-octave-band values of response level and latency were estimated. Our main finding was that in ears with spontaneous activity, TBOAEs had higher levels than in ears without. The difference was more apparent for global values, but were also seen with half-octave-band analysis. Input/output functions had similar growth rates for ears with and without SSOAEs. There were no significant differences in latencies between TBOAEs from ears with and without SSOAEs, although latencies tended to be longer for lower stimulus levels and lower stimulus frequencies. When TBOAE levels were compared to CEOAE levels, the latter showed greater differences between recordings from ears with and without SSOAEs. Although TBOAEs reflect activity from a more restricted cochlear region than CEOAEs, at all stimulus frequencies their behavior still depends on whether SSOAEs are present or not.

The 1.06 frequency ratio in the cochlea: evidence and outlook for a natural musical semitone

A frequency ratio of about 1.06 often appears in cochlear mechanics, and the question naturally arises, why? The ratio is close to that of the semitone (1.059) in music, giving reason to think that this aspect of musical perception might have a cochlear basis. Here, data on synchronised spontaneous otoacoustic emissions is presented, and a clustering of ratios between 1.05 and 1.07 is found with a peak at 1.063 ± 0.005. These findings reinforce what has been found from previous sources, which are reviewed and placed alongside the present work. The review establishes that a peak in the vicinity of 1.06 has often been found in human cochlear data. Several possible cochlear models for explaining the findings are described. Irrespective of which model is selected, the fact remains that the cochlea itself appears to be the origin of a ratio remarkably close to an equal-tempered musical semitone, and this close coincidence leads to the suggestion that the inner ear may play a role in constructing a natural theory of music. The outlook for such an enterprise is surveyed.

Heightened visual attention does not affect inner ear function as measured by otoacoustic emissions

Previous research has indicated that inner ear function might be modulated by visual attention, although the results have not been totally conclusive. Conceivably, modulation of hearing might occur due to stimulation of the cochlea via descending medial olivocochlear (MOC) neurons. The aim of the present study was to test whether increased visual attention caused corresponding changes in inner ear function, which was measured by the strength of otoacoustic emissions (OAEs) recorded from the ear canal in response to a steady train of clicks. To manipulate attention, we asked subjects to attend to, or ignore, visual stimuli delivered according to an odd-ball paradigm. The subjects were presented with two types of visual stimuli: standard and deviant (20% of all stimuli, randomly presented). During a passive part of the experiment, subjects had to just observe a pattern of squares on a computer screen. In an active condition, the subject's task was to silently count the occasional inverted (deviant) pattern on the screen. At all times, visual evoked potentials (VEPs) were used to objectively gauge the subject's state of attention, and OAEs in response to clicks (transiently evoked OAEs, TEOAEs) were used to gauge inner ear function. As a test of descending neural activity, TEOAE levels were evaluated with and without contralateral acoustic stimulation (CAS) by broadband noise, a paradigm known to activate the MOC pathway. Our results showed that the recorded VEPs were, as expected, a good measure of visual attention, but even when attention levels changed there was no corresponding change in TEOAE levels. We conclude that visual attention does not significantly affect inner ear function.

Round window stimulation with the Vibrant Soundbridge: Comparison of direct and indirect coupling

OBJECTIVES/HYPOTHESIS

The purpose of this study was to measure the degree of coupling between the floating mass transducer (FMT) and the round window membrane (RWM) in patients with conductive and mixed hearing loss implanted with the Vibrant Soundbridge (VSB) device. The efficiency of direct and indirect coupling of the FMT to the RWM was compared by measuring differences between the initial prescription targets and the final settings of the VSB audio processor after fine-tuning.

STUDY DESIGN

Retrospective study.

METHODS

Investigation of a group of subjects with either conductive or mixed hearing loss implanted with the VSB, a device that uses a FMT coupled to the RWM. There were two subgroups: subjects in which coupling was direct (no interposed material) or indirect (interposed material). The functional gain, insertion gain, and compression characteristics of the device were measured to assess the efficiency of coupling and to investigate the proximity of the fitting to prescriptive targets.

RESULTS

Coupling for the subgroup with indirect coupling of the RWM was higher (better) than for the subgroup with direct coupling. The gain deviation from prescriptive targets was smaller for the subgroup with indirect coupling.

CONCLUSIONS

The coupling method can have an effect on the coupling efficiency and the final electroacoustic settings of the device. The prescription targets were not accurate for the majority of subjects from either subgroup. Indirect coupling appears to provide more effective stimulation of the cochlea.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2843-2849, 2017.

Spontaneous otoacoustic emissions in schoolchildren

OBJECTIVE

Spontaneous otoacoustic emissions (SOAEs) are one of the least studied types of otoacoustic emissions (OAEs). The purpose of this study was twofold: first, to determine the prevalence of SOAEs in schoolchildren, and second to test whether there was dependence between the presence or absence of SOAEs in a subject and the corresponding level of their transiently evoked OAEs (TEOAEs).

METHODS

Measurements were made on a group of normally hearing children of age 7-13 years. A technique which detects synchronized SOAEs (SSOAEs) was used in which the response to repetitive clicks (12.5/s) was analyzed in the 60-80 ms time window following each click. The matching pursuit method was used to detect SSOAEs components above the noise in this window. For comparison, TEOAEs evoked by clicks (40/s) were obtained using the standard nonlinear protocol (20 ms time window).

RESULTS

The prevalence of SOAEs was 37%, and higher in females and right ears. There was an average of 2.3 SOAEs per emitting ear. TEOAE levels were higher for ears that had SOAEs and were lower for ears that did not have any SOAEs.

CONCLUSION

Although not all normal human have SOAEs, they appear to reflect an important aspect of cochlear function. Their presence is strongly related to elevated levels of TEOAEs which are routinely used in audiological tests.

Criteria for detection of transiently evoked otoacoustic emissions in schoolchildren

OBJECTIVES

The aim was to compare, on the same dataset, existing detection criteria for transiently evoked otoacoustic emissions (TEOAEs) and to select those most suitable for use with school-aged children.

METHODS

TEOAEs were recorded from the ears of 187 schoolchildren (age 8-10 years) using the Otodynamics ILO 292 system with a standard click stimulus of 80dB peSPL. Pure tone audiometry and tympanometry were also conducted. Global and half-octave-band (at 1, 1.4, 2, 2.8, 4kHz) values of OAE signal-to-noise ratio (SNR), reproducibility, and response level were determined. These parameters were used as criteria for detection of TEOAEs. In total, 21 criteria based on the literature and 3 new ones suggested by the authors were investigated.

RESULTS

Pure tone audiometry and tympanometry screening generated an ear-based failure rate of 7.49%. For TEOAEs, there was a huge variability in failure rate depending on the criteria used. However, three criteria sets produced simultaneous values of sensitivity and specificity above 75%. The first of these criteria was based only on a global reproducibility threshold value above 50%; the second on certain global reproducibility and global response values; and the third involved exceeding a threshold of 50% band reproducibility. The two criteria sets with the best sensitivity were based on global reproducibility, response level, and signal-to-noise ratio (with different thresholds across frequency bands).

CONCLUSIONS

TEAOEs can be efficiently used to test the hearing of schoolchildren provided appropriate protocols and criteria sets are used. They are quick, repeatable, and simple to perform, even for nonaudiologically trained personnel. Criteria with high sensitivity (89%) were identified, but they had relatively high referral rates. This is not so much a problem in schoolchildren as it is in newborns because with schoolchildren pure tone audiometry and tympanometry can be performed immediately or at a follow-up session. Nevertheless, high referral rates lead to increased screening cost; for that reason, three less rigorous criteria with high values of both sensitivity and specificity (75% and above) are recommended.

Tone burst evoked otoacoustic emissions in different age-groups of schoolchildren

INTRODUCTION

Otoacoustic emissions (OAEs) are believed to be good predictors of hearing status, particularly in the 1-4kHz range. However both click evoked OAEs (CEOAEs) and distortion product OAEs (DPOAEs) perform poorly at 0.5kHz. The present study investigates OAEs in the lower frequency range of 0.5-1kHz evoked by 0.5kHz tone bursts (TBOAEs) in schoolchildren and compares them with emissions evoked by clicks.

METHODS

Measurements were performed for two groups of normally hearing schoolchildren. Children from 1st grade (age 6-7 years) and children from 6th grade (age 11-12 years). Tympanometry, pure tone audiometry, and OAE measurements of CEAOEs, 0.5kHz TBOAEs, and spontaneous OAEs (SOAEs) were performed. Additionally, analysis by the matching pursuit method was conducted on CEOAEs and TBOAEs to assess their time-frequency (TF) properties.

RESULTS

For all subjects OAEs response levels and signal to noise ratios (SNRs) were calculated. As expected, CEOAE magnitudes were greatest over the range 1-4kHz, with a substantial decrease below 1kHz. Responses from the 0.5kHz TBOAEs were complementary in that the main components occurred between 0.5 and 1.4kHz. In younger children, TBOAEs had SNRs 4-8dB smaller in the 0.5-1.4kHz range. In addition, CEOAEs had lower SNRs in the 0.7-1.4kHz range, by 3-5dB. TBOAEs in younger children had maximum SNRs shifted toward 1-1.4kHz, whereas in older children it was more clearly around 1kHz. The differences in response levels were less evident. The presence of SOAEs appreciably influenced both CEOAEs and TBOAEs, and TF properties of both OAEs did not differ significantly between grades.

CONCLUSION

TBOAEs evoked at 0.5kHz can provide additional information about frequencies below 1kHz, a range over which CEOAEs usually have very low amplitudes. The main difference between the two age groups was that in older children CEOAEs and 0.5kHz TBOAEs had higher SNRs at 0.5-1.4kHz. Additionally, for ears with SOAEs, 0.5kHz TBOAEs had higher response levels and SNRs similar to CEOAEs.

IL-10 promoter polymorphisms influence susceptibility to aGvHD and are associated with proportions of CD4+FoxP3+ lymphocytes in blood after hematopoietic stem cell transplantation

Four hundred and ninety-five patients (390 and 105 grafted from unrelated and sibling (SIB) donors, respectively) and their donors were analyzed for the impact of interleukin-10 (IL-10) promoter genotype [rs18000896 (-1082 G/A), rs18000871 (-819 C/T) and rs18000872 (-592 C/A)] on the outcome of hematopoietic stem cell transplantation (HSCT). Patients having ACC haplotype were at a lower risk of acute graft versus host disease (aGvHD, grade > I) if transplanted from human leukocyte antigen (HLA) well-matched (10/10) unrelated donors (20/135 vs 39/117, P < 0.001, Pcorr = 0.002), which was not seen if patients were transplanted from either sibling (SIB) or poorly matched (<10/10) unrelated donors (MUD). In addition, GCC haplotype positive recipients of unrelated donor transplants tended to be more susceptible to aGvHD (68/199 vs 39/169, P = 0.019, Pcorr = 0.057). Multivariate logistic regression analysis in the MUD transplanted group showed that donor-recipient human leukocyte antigen (HLA) mismatch [odds ratio (OR) = 3.937, P = 0.001] and a lack of ACC haplotype in recipients (OR = 0.417, P = 0.013) played a significant role as independent risk factors of aGvHD grade > I. ACC carriers had higher proportions of FoxP3+ lymphocytes gated in CD4+ lymphocytes as compared with patients with other IL-10 haplotypes. It was seen at the time of hematological recovery (mean ± SEM: 3.80 ± 0.91% vs 2.06 ± 0.98%, P = 0.012) and 2 weeks later (5.32 ± 0.87% vs 2.50 ± 0.83%, P = 0.013); -592 C/A polymorphism was separately analyzed and it was found that AA homozygotes tended to have a higher incidence of aGvHD (8/15 vs 116/456, P = 0.034) and low proportions of FoxP3 CD4+ lymphocytes in blood (0.43 ± 0.22% vs 4.32 ± 0.71%, P = 0.051) measured 2 weeks after hematological recovery. Functional IL-10 polymorphism associated features influenced the risk of aGvHD with a positive effect of ACC on the pool of Treg in blood.

Low-frequency otoacoustic emissions in schoolchildren measured by two commercial devices

OBJECTIVE

Click evoked otoacoustic emissions in children are known to be good indicators of hearing function when used in the frequency range 1.5-4 kHz. Using two commercial devices, the present study investigates the usefulness of responses in the lower frequency range of 0.5-1 kHz evoked by 0.5 kHz tone bursts.

METHODS

Otoacoustic emissions (OAEs) were recorded from the ears of 37 schoolchildren (age 12-13 years). OAE measurements were then made using two devices: the ILO 292 (Otodynamics) and the HearId (Mimosa Acoustics). Each device was used for two measurements: first with a standard click stimulus at 80 dB pSPL (CEOAEs) and a second using a 0.5 kHz tone burst at 80 dB pSPL (TBOAEs). Pure tone audiometry and tympanometry were also conducted. Half-octave-band values of OAE signal to noise ratios (SNRs) and response levels were used to assess statistical differences.

RESULTS

Both devices provided similar SNR results for click and tone burst stimuli, although the ILO device generated slightly higher response levels for clicks. For the 0.5 kHz tone bursts, both devices evoked very weak responses at 0.5 kHz and the peak response occurred at 0.7-1 kHz. Generally, CEOAE SNRs were about 10 dB in the 1-4 kHz range, while SNRs for 0.5 kHz TBOAEs were about 10 dB at 0.7-1 kHz.

CONCLUSIONS

0.5 kHz TBOAEs could be measured in children as effectively as CEOAEs. They can provide additional information about the 0.7-1 kHz frequency range, a range over which CEOAEs do not usually contain responses above the noise floor. The main difficulty was that the maxima of the 0.5 kHz TBOAEs occurred at frequencies of 0.7-1 kHz, probably because of spectral splatter from the short tone burst stimulus and from rapidly falling responses of the cochlea and the recording system at low frequencies.

Automatic removal of sonomotor waves from auditory brainstem responses

We have developed a computerized technique for automatic detection and removal of sonomotor waves (SMWs) from auditory brainstem responses (ABRs). Our approach is based on adaptive decomposition using a redundant set of Gaussian and 1-cycle-limited Gabor functions. In order to find optimal parameters and evaluate the efficiency of the methods, simulated data were first used before applying it to clinical data. Results were good and confirmed by an expert with years of clinical experience in ABR evaluation.

Chirp-evoked otoacoustic emissions in children

OBJECTIVE

The purpose of the study was to investigate the properties of otoacoustic emissions (OAEs) evoked by chirp stimuli and compare them with standard click-evoked OAEs. Differences between evoked OAEs in children with and without spontaneous otoacoustic emissions (SOAEs) were also assessed.

METHODS

OAEs were first recorded from 54 children (age 4-10 years) in a screening setup. In each ear five OAE measurements were made using two types of chirps (7.5 ms and 10.5 ms) at around 70 dB pSPL; clicks at 70 and 80 dB pSPL; and a standard synchronized SOAE stimulation protocol. Tympanometry was also conducted. Pass/refer criteria based on signal to noise ratios (SNRs) were applied to all OAEs. Pass/refer rates from all methods (OAEs evoked by chirps and clicks, and tympanometry) were compared. Additionally, half-octave-band values of OAE SNRs and response levels were used to assess statistical differences.

RESULTS

Chirp-evoked OAEs generated a similar number of passes to click-evoked OAEs when the same level of stimulus was used. When using lower stimulus levels, both chirp- and click-evoked OAEs diagnosed nearly all ears that failed tympanometry. The response levels and SNRs of OAEs evoked by clicks and chirps were very similar. The highest response levels were in the 1.4 kHz half-octave band. The SNRs for ears with SOAEs were highest at 1.4 kHz, whereas they were at 4 kHz for ears without SOAEs. Both response levels and SNRs were higher by about 5 dB for ears with SOAEs than ears without SOAEs. Also all ears with SOAEs generated a pass result in screening, while ears without SOAEs gave a pass less frequently (at least 30% fewer cases).

CONCLUSIONS

The results suggest that performance of chirp-evoked OAEs for screening purposes is similar to click-evoked OAEs when the same stimulus level is applied. OAEs evoked with lower stimulus levels (70 vs. 80 dB pSPL) are more sensitive to middle ear pathology. The presence of SOAEs significantly influences the pass rates of OAEs evoked by chirps and clicks.

Otoacoustic emissions in neonates measured with different acquisition protocols

OBJECTIVE

The purpose of the study was to investigate the properties of neonatal transiently evoked otoacoustic emissions (TEOAEs) recorded with three most popular stimulation protocols. Differences between the recorded TEOAEs with and without spontaneous otoacoustic emissions (SOAEs), were also assessed. In addition two more issues were addressed: (i) the effect of windowing on the TEOAE responses; and (ii) the contribution of the TEOAE segment from 12.5 to 20 ms to the overall TEOAE response.

METHODS

TEOAEs and SOAEs were recorded from 50 normal hearing neonates using linear, non-linear, QuickScreen and standard synchronized SOAE stimulation protocols. Global and half-octave-band values of TEOAE reproducibility and response level were used to assess statistical differences in the recorded responses. Furthermore protocol differences were evaluated in different recording windows from 2.5 to 12.5 and 12 to 20 ms.

RESULTS

Data from the linear protocol presented TEOAE parameters with the highest values. The differences between recordings with longer and shorter acquisition windows were especially apparent in 1-1.4 kHz frequency range. Furthermore the data have shown that the low frequency TEOAE components are a significant part of the TEOAE response, especially in ears without SOAEs.

CONCLUSIONS

The results suggest that TEOAE protocols using short recording windows (i.e. QuickScreen) can be used only for a fast detection of a valid TEOAE. For more sophisticated clinical analyses the standard 20 ms TEOAE recording window is more appropriate. The presence of SOAEs significantly influences TEOAEs. Ears with SOAEs presented higher values of TEOAE parameters especially in the 2-4 kHz range. On the other hand, in the ears without SOAEs low frequency components contribute more to the signal.

Time-frequency analysis of linear and nonlinear otoacoustic emissions and removal of a short-latency stimulus artifact

Click-evoked otoacoustic emissions (CEOAEs) are commonly recorded as average responses to a repetitive click stimulus. If the click train has constant polarity, a linear average results; if it contains a sequence of clicks of differing polarity and amplitude, a nonlinear average can be calculated. The purpose of this study was to record both protocols from the same set of ears and characterize the differences between them. The major features of CEOAEs were similar under both protocols with the exception of a region spanning 0-5 ms in time and 0-2.2 kHz in frequency. It was assumed that the signal derived from the linear protocol was contaminated by stimulus artifact, and so a simple procedure was used--involving high-pass filtering and time-windowing--to remove components of this artifact. This procedure preserved the short-latency, high-frequency responses; it also produced a marked similarity in the time-frequency plots of recordings made under the two protocols. This result means it is possible to take advantage of the better signal-to-noise ratio of the linear data compared to its nonlinear counterpart. Additionally, it was shown that CEOAEs recorded under the linear protocol appear to be less dependent on the presence of spontaneous otoacoustic emissions (SOAEs).

Use of the matching pursuit algorithm with a dictionary of asymmetric waveforms in the analysis of transient evoked otoacoustic emissions

Transiently evoked otoacoustic emissions (TEOAEs) are normally modeled as the sum of asymmetric waveforms. However, some previous studies of TEOAEs used time-frequency (TF) methods to decompose the signals into symmetric waveforms. This approach was justified mainly as a means to reduce the complexity of the calculations. The present study extended the dictionary of numeric functions to incorporate asymmetric waveforms into the analysis. The necessary calculations were carried out using an adaptive approximation algorithm based on the matching pursuit (MP) numerical technique. The classic MP dictionary uses Gabor functions and consists of waveforms described by five parameters, namely, frequency, latency, time span, amplitude, and phase. In the present investigation, a sixth parameter, the degree of asymmetry, was added in order to enhance the flexibility of this approach. The effects of expanding the available functions were evaluated by means of both simulations using synthetic signals and authentic TEOAEs. The resulting analyses showed that the contributions of asymmetric components in the OAE signal are appreciable. In short, the expanded analysis method brought about important improvements in identifying TEOAE components including the correct detection of components with long decays, which are often related to spontaneous OAE activity, the elimination of a "dark energy" effect in TF distributions, and more reliable estimates of latency-frequency relationships. The latter feature is especially important for correct estimation of latency-frequency data, which is a crucial factor in investigations of OAE-generation mechanisms.

Otoacoustic emissions evoked by 0.5 kHz tone bursts

The aim of this research is to extend previous studies of the time-frequency features of otoacoustic emissions (OAEs) using information about the properties of the signals at low frequencies. Responses to 0.5 kHz tone bursts were compared to OAEs that were evoked by click stimuli and by 1, 2, and 4 kHz tone burst stimuli. The OAEs were measured using 20 and 30 ms intervals between stimuli. The analysis revealed no differences in the time-frequency properties of 1, 2, and 4 kHz bursts measured using these two different acquisition windows. However, at 0.5 kHz the latency of the response was affected significantly if a shorter time window was used. This was caused by the fact that the response reached a maximum after an average time of 15.4 ms, and lasted a few milliseconds longer. Therefore, for this particular stimulus, the use of a 30 ms time window seems more appropriate. In addition, as an example of the possible application of low-frequency OAEs, signals were measured in patients suffering from partial deafness, characterized by steep audiograms with normal thresholds up to 0.5 kHz and almost total deafness above this frequency. Although no response to clicks was observed in these subjects, the use of 0.5 kHz tone bursts did produce OAEs.

Synchronized spontaneous otoacoustic emissions analyzed in a time-frequency domain

A synchronized spontaneous otoacoustic emission paradigm was used to measure the response in time intervals of 80 ms following a click stimulus. The responses obtained were decomposed into basic waveforms by means of adaptive approximations using a matching pursuit algorithm. High-resolution time-frequency distributions of signal energy were calculated and showed three types of component: (1) purely evoked of duration less than 5 ms, (2) longer lasting and decaying, with exponentially decreasing amplitude, and (3) long lasting and stable. The distributions of the frequencies of components of different durations were similar, with most components falling within the 1-2 kHz interval. It is shown that the presence of long-lasting components may influence the estimation of the latency of evoked emissions, especially at higher frequencies where the evoked part has a very short duration.

Origin of suppression of otoacoustic emissions evoked by two-tone bursts

Otoacoustic emission (OAE) data recorded for tone bursts presented separately and as a two-tone burst complex, that had been reported previously [Yoshikawa, H., Smurzynski, J., Probst R., 2000. Suppression of tone burst evoked otoacoustic emissions in relation to frequency separation. Hear. Res. 148, 95-106], were re-processed using the method of adaptive approximations by matching pursuit (MP). Two types of stimuli were applied to record tone burst OAEs (TBOAEs): (a) cosine-windowed tone bursts of 5-ms duration with center frequencies of 1, 1.5, 2 and 3kHz, (b) complex stimuli consisting of a digital addition of the 1-kHz tone burst together with either the 1.5-, 2- or 3-kHz tone burst. The MP method allowed decomposition of signals into waveforms of defined frequency, latency, time span, and amplitude. This approach provided a high time-frequency (t-f) resolution and identified patterns of resonance modes that were characteristic for TBOAEs recorded in each individual ear. Individual responses to single-tone bursts were processed off-line to form 'sum of singles' responses. The results confirmed linear superposition behavior for a frequency separation of two-tone bursts of 2kHz (the 1-kHz and 3-kHz condition). For the 1, 1.5-kHz condition, the MP results revealed the existence of closely positioned resonance modes associated with responses recorded individually with the stimuli differing in frequency by 500Hz. Then, the differences between t-f distributions calculated for dual (two-tone bursts) and sum-of-singles conditions exhibited mutual suppression of resonance modes common to both stimuli. The degree of attenuation depended on the individual pattern of characteristic resonance modes, i.e., suppression occurred when two resonant modes excited by both stimuli overlapped. It was postulated that the suppression observed in case of dual stimuli with closely-spaced components is due to mutual attenuation of the overlapping resonance modes.

Resonant modes of otoacoustic emissions

Transiently evoked otoacoustic emission (TEOAE) signals were decomposed into basic components by means of the matching pursuit algorithm. The components were characterized by frequency, latency, time span and energy. The resonant modes characteristic for each person/ear were identified. A high time-frequency resolution of the method and the parametric representation of the waveforms made possible estimation of the frequency ratios of the resonant modes. The repetitive occurrence of the 'fifth', 'fourths' and octaves connected with the Pythagorean temperament was found. The significance of the results was confirmed by comparison to Monte Carlo simulations of the null hypothesis of a random distribution of frequency modes. These findings are in agreement with the resonance theory of hearing, which binds musical ratios with the geometrical spacing of outer hair cells in cochlea.

The influence of palifermin (Kepivance) on oral mucositis and acute graft versus host disease in patients with hematological diseases undergoing hematopoietic stem cell transplant

In this multicenter study, we assessed the use of palifermin (recombinant human-keratinocyte growth factor 1) in the prevention of oral mucositis (OM) and acute GvHD (aGvHD) induced by a hematopoietic stem cell transplant (HSCT). Fifty-three patients with hematological diseases received three doses of palifermin (60 mug/kg once daily i.v.) pre- and post-conditioning regimens (total six doses). A retrospective control group of 53 transplant patients received no palifermin. There was a significant reduction in the incidence of OM of WHO (World Health Organization) grades 1-4 (58 vs 94%, P<0.001), 3-4 (13 vs 43%, P<0.001) and the median duration of OM (4 vs 9 days, P<0.001) in the palifermin group compared to the control group. The incidence of analgesics (32 vs 75.5%, P<0.001), opioid analgesics (24 vs 64%, P<0.001) and total parenteral nutrition (11 vs 45%, P<0.001) was also significantly reduced. The analysis of distribution of affected organs revealed that aGvHD was less prevalent in the palifermin group (P=0.036). There was no significant difference in the onset of any OM after HSCT, time to engraftment and length of hospitalization between groups. The drug was generally well tolerated and safe. Our results suggest that the use of palifermin reduces OM and probably aGvHD after HSCT, but a randomized trial is needed.

Otoacoustic emissions latency difference between full-term and preterm neonates

Transiently evoked otoacoustic emissions (TEOAEs) were recorded from full-term and preterm neonates. The responses were decomposed, by means of an adaptive approximation method, into waveforms of defined frequencies, amplitudes, latencies and time spans. Statistically significant differences in the latency values were found between the tested groups. Differences were also found in the time spans of the TEOAEs components. For the preterm neonates the contribution of long-duration components (i.e. long-time span) was higher. Those components were characterized by narrow frequency band and contrary to the short-time span components their latencies did not depend on frequency. The removal of the long-duration components, from the pool of analyzed data, decreased the latency differences between the tested groups. The results indicate that the origin of the longer latency values for preterm neonates (with a post conceptional age up to 33 weeks) in respect to full-term neonates can be attributed to the presence of long-lasting components. The correspondence, which was found between frequencies of long-duration components and the spectral peaks of spontaneous otoacoustic emissions (SOAEs), suggests that those components may be connected with SOAEs.

Time-frequency analysis of transiently evoked otoacoustic emissions of subjects exposed to noise

Transiently evoked otoacoustic emissions (TEOAE) were measured from 124 ears from two subject groups: healthy subjects (62 ears), and workers (62 ears) exposed to noise of jet engines. The recordings were analyzed using the method of adaptive approximations based on a matching pursuit (MP) algorithm. The method allows for description of the signal components in terms of their amplitude, frequency, latency, and time-span (or duration). The purpose of this work was to determine the repeatability and usefulness of these parameters in studies of hearing impairment of populations exposed to potentially harmful noise. Good distinction between the two datasets was achieved in all investigated frequency bands when amplitude was used as a discrimination parameter. Also latency was affected in frequency bands starting at 2000 Hz, while the time-span parameter associated with the duration of the waveform was less influenced by noise.

Resonant modes in transiently evoked otoacoustic emissions and asymmetries between left and right ear

A number of single-frequency resonant modes in click evoked otoacoustic emissions (OAEs) was investigated. The OAE modes were identified by means of an adaptive approximation method based on the matching pursuit (MP) algorithm. The signals were decomposed into basic waveforms coming from a very large and redundant dictionary of Gabor functions. The study was performed on transiently evoked otoacoustic emissions (TEOAEs) from left and right ears of 108 subjects. The correspondence between waveforms found by the procedure and resonant modes was shown (both for simulated noisy data and for single-person TEOAEs). The decomposition of TEOAEs made distinction between short and long-lasting components possible. The number of main resonant modes was studied by means of different criteria and they all led to similar results, indicating that the main features of the signal are explained on average by 10 waveforms. The same number of resonant modes for the right ear accounted for more energy than for the left ear.

Outcome of treatment in adults with Philadelphia chromosome-positive and/or BCR-ABL--positive acute lymphoblastic leukemia-retrospective analysis of Polish Adult Leukemia Group (PALG)

Patients with Philadelphia chromosome-positive (Ph+) and/or BCR-ABL+ acute lymphoblastic leukemia (ALL) have extremely poor prognoses. Most of these patients have additional, heterogenous karyotype abnormalities, the majority of which have uncertain clinical significance. In this study we analyzed the clinical characteristics, karyotype abnormalities, and outcome of 77 patients with Ph+ and/or BCR-ABL+ ALL registered in Poland in 1997-2004. In 31/55 patients with known karyotype, the sole t(9;22)(q34;q11) abnormality had been diagnosed; in one patient, variant translocation t(4;9;22)(q21q31.1;q34;q11), and additional abnormalities in 23 (42%) patients, had been diagnosed. The characteristics of the patients with Ph chromosome and additional abnormalities were not significantly different when compared with the entire analyzed group. Out of 77 patients, 54 (70%) achieved first complete remission (CR1) after one or more induction cycles. The overall survival (OS) probability of 2 years was 63, 43, and 17% for patients treated with allogeneic stem cell transplantation (alloSCT), autologous SCT, and chemotherapy, respectively (log rank p=0.002). Median OS from the time of alloSCT was significantly longer for patients transplanted in CR1 compared with alloSCT in CR >1 (p=0.032). There were no significant differences in CR rate, disease-free survival (DFS), and OS for patients with t(9;22) and additional abnormalities compared with the whole group. Only WBC >20 G/l at diagnosis adversely influenced OS probability (log rank p=0.0017). In conclusion, our data confirm poor outcome of Ph+ and/or BCR-ABL+ ALL. Only patients who received alloSCT in CR1 had longer DFS and OS. We have shown that additional karyotype abnormalities did not influence the clinical characteristics of the patients; however, their influence on treatment results needs to be further assessed.

Addition of cladribine to induction/consolidation regimen does not impair peripheral blood stem cell mobilization and bone marrow harvest for autotransplantation in acute myeloid leukemia patients

BACKGROUND

The previous study by the Polish Adult Leukemia Group has demonstrated that addition of cladribine to standard DNR+AraC induction potentiates the antileukemic activity. The goal of this study was to compare the efficacy of bone marrow or peripheral blood hematopoietic cell collection in patients who obtained remission after daunorubicine plus cytarabine induction with cladribine (DAC-7) or without addition of cladribine (DA-7) in preparation for autotransplantation.

PATIENTS AND METHODS

Sixty-six patients aged 41 years (range, 17-58 years) were included in this study: 33 cases in the DAC-7 and 33 in the DA-7 arm. Hematopoietic cells were collected from the bone marrow (ABMT, n = 29) or from the peripheral blood (ABCT, n = 37) using cytopheresis after administration of AraC (2 x 2 g/m2) on days 1, 3, 5 and subsequent G-CSF (10 microg/kg) from day 7 as mobilization therapy.

RESULTS

The numbers of harvested CD34+ cells were similar in the DAC-7 and DA-7 pretreated patients both after harvesting from peripheral blood (2.55 x 10(6)/kg vs 2.5 x 10(6)/kg) and from bone marrow (1.62 x 10(6)/kg vs 1.55 x 10(6)/kg), respectively. The proportion of patients with sufficient material for autologous bone marrow transplantation was higher in the DAC-7 compared with the DA-7 arm. All patients engrafted; hematopoietic recovery was similar in both subgroups.

CONCLUSION

Addition of cladribine to a standard DA induction does not impair the harvesting of hematopoietic cells and their engraftment after autotransplantation.

Resonant modes and musical ratios in otoacoustic emissions

The ratios between frequency components of evoked otoacoustic emissions (OAE) were investigated for 100 ears. The signals were decomposed by means of an adaptive approximation method into basic waveforms coming from a very large and redundant dictionary of Gabor functions. The high time-frequency resolution of the method and the parametric representation of the waveforms allowed for an estimation of the frequency ratios of the basic components. A repetitive occurrence of the "fifths", "fourths" and octaves connected with the Pythagorean temperament was found. The octaves containing "fifths" were identified. This kind of sequences in OAE tend to appear in the same form for tonal stimulations of different frequencies and for broadband stimuli. The significance of the results was confirmed by comparison to Monte Carlo simulations of the null hypothesis of random distribution of frequency modes. These findings support the resonance theory of hearing, which binds musical ratios with the geometrical spacing of outer hair cells in the cochlea.

Primary lymphoma of the liver -- morphological and clinical analysis of 6 cases. Success of aggressive treatment

Histological, clinical and immunohistochemical analysis of 6 cases of primary liver lymphomas (PLL) are presented. PLL represents 4.3% of primary malignant liver tumors diagnosed in our department. The patients were relatively young people, who despite the presence of a large tumor, were in good general health status. There were no signs of scirrhosis, and cancer markers were normal. All lymphomas were CD20, CD79a, BAX positive, CD3, CD30, EMA, CD10, CD5, CD59, c-myc, Bcl2, EBV(LMP), CK negative. The proliferation index (Ki67) was high, ranging from 50-100%. In two cases positive staining for Bcl6 and in another one for cyclin D1 was obtained. The major histological type of the tumor was diffuse large B-cell lymphoma. Positive immunohistochemical results with BAX and the lack of Bcl2, c-myc and CD59 are associated with better prognosis. We have not confirmed the value of Bcl6 and CD10 stains as a predictor of poor outcome. Despite clinically advanced stage at the time of diagnosis, if treated appropriately, the primary lymphoma of the liver has relatively good prognosis (five of our patients are alive).