Hearing Impairment in the Extended High Frequencies in Children Despite Clinically Normal Hearing

Extended High-Frequency Audiometry Using the Wireless Automated Hearing Test System Compared to Manual Audiometry in Children and Adolescents

OBJECTIVES

Valid wireless automated Békésy-like audiometry (ABA) outside a sound booth that includes extended high frequencies (EHF) would increase access to monitoring programs for individuals at risk for hearing loss, particularly those at risk for ototoxicity. The purpose of the study was to compare thresholds obtained with (1) manual audiometry using an Interacoustics Equinox and modified Hughson-Westlake 5 dB threshold technique to automated audiometry using the Wireless Automated Hearing Test System (WAHTS) and a Békésy-like 2 dB threshold technique inside a sound booth, and (2) ABA measured in the sound booth to ABA measured outside the sound booth.

DESIGN

Cross-sectional study including 28 typically developing children and adolescents (mean = 14.5 years; range = 10 to 18 years). Audiometric thresholds were measured from 0.25 to 16 kHz with manual audiometry inside the sound booth and with ABA measured both inside and outside the sound booth in counterbalanced order.

RESULTS

ABA thresholds measured inside the sound booth were overall about 5 dB better compared with manual thresholds in the conventional frequencies (0.25 to 8 kHz). In the EHFs (10 to 16 kHz), a larger threshold difference was observed, where ABA thresholds were overall about 14 dB better compared with manual thresholds. The majority of ABA thresholds measured outside the sound booth were within ±10 dB of ABA thresholds measured inside the sound booth (conventional: 86%; EHF: 80%). However, only 69% of ABA thresholds measured inside the sound booth were within ±10 dB of manual thresholds in the conventional frequencies and only 32% of ABA thresholds measured inside the sound booth were within ±10 dB of manual thresholds in the EHFs.

CONCLUSIONS

These results indicate that WAHTS ABA results in better thresholds in conventional frequencies than manual audiometry in children and adolescents, consistent with previous studies in adults. Hearing thresholds for the EHF were better when measured with WAHTS ABA compared with manual audiometry, likely due to different transducer-related calibration values that are not age-adjusted. Additional studies of WAHTS automated Békésy-like EHF thresholds that include healthy pediatric participants are needed to establish age-appropriate normative thresholds for clinical application in monitoring programs for noise-induced hearing loss and/or ototoxicity.

Association of Polycystic Ovary Syndrome With Sensorineural Hearing Loss: A Systematic Review and Meta-analysis

OBJECTIVE

Despite certain studies indicating hearing impairments in individuals with polycystic ovary syndrome (PCOS), the correlation between PCOS and sensorineural hearing loss (SNHL) remains inconclusive. This study aimed to investigate the association between PCOS and SNHL.

DATA SOURCES

A systematic literature search was conducted using PubMed, MEDLINE, EMBASE, and the Cochrane Library from inception to June 24, 2024.

REVIEW METHODS

This meta-analysis included cross-sectional, case-control, or cohort studies examining the association between PCOS and SNHL without language or regional restrictions. Case reports, case series, animal studies, and in vitro studies were excluded. We adhered to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and utilized the Newcastle-Ottawa Scale to assess the risk of bias in the included studies.

RESULTS

After performing the systematic review, we conducted a meta-analysis that included 489 patients from 5 studies: 349 patients with PCOS and 140 age- and sex-matched controls without PCOS. The meta-analysis compared the mean differences in frequency-specific pure-tone thresholds between patients with PCOS and matched controls, providing 95% confidence intervals for these differences. Given the expected clinical heterogeneity, we employed the DerSimonian and Laird random-effects model. Our results revealed significant hearing loss at specific frequencies (1000, 4000, 8000, 10,000, 12,000, 14,000, 16,000, 18,000, and 20,000 Hz) in the PCOS group compared to the control group (P < .05). Furthermore, the degree of hearing loss is greater at higher frequencies.

CONCLUSION

This meta-analysis demonstrated an association between PCOS and SNHL, particularly at higher frequencies.

Extended high-frequency hearing and suprathreshold neural synchrony in the auditory brainstem

Elevated hearing thresholds in the extended high frequencies (EHFs) (>8 kHz) are often associated with poorer speech-in-noise recognition despite a clinically normal audiogram. However, whether EHF hearing loss is associated with disruptions in neural processing within the auditory brainstem remains uncertain. The objective of the present study was to investigate whether elevated EHF thresholds influence neural processing at lower frequencies in individuals with normal audiograms. Auditory brainstem responses (ABRs) were recorded at a suprathreshold level (80 dB normal hearing level) from 45 participants with clinically normal hearing. The recording protocol was optimized to obtain robust wave I of the ABR. Results revealed no significant relationship between the pure tone average for EHFs and any ABR metrics at either rate, while adjusting for the effects of age, sex, and hearing thresholds at standard frequencies (0.25-8 kHz). Rate-dependent significant sex effects for wave I and V amplitude, I-V amplitude ratio, and III and V latency were observed. Elevated EHF hearing thresholds do not significantly affect the brainstem processing in the lower frequencies (<8 kHz).

The relationship between distortion product otoacoustic emissions and audiometric thresholds in the extended high-frequency range

Distortion product otoacoustic emissions (DPOAEs) and behavioral audiometry are routinely used for hearing screening and assessment. These measures provide related information about hearing status as both are sensitive to cochlear pathologies. However, DPOAE testing is quicker and does not require a behavioral response. Despite these practical advantages, DPOAE testing is often limited to screening only low- and mid-frequencies. Variation in ear canal acoustics across ears and probe placements has resulted in less reliable measurements of DPOAEs near 4 kHz and above where standing waves commonly occur. Stimulus calibration in forward pressure level and responses in emitted pressure level can reduce measurement variability. Using these calibrations, this study assessed the correlation between audiometry and DPOAEs in the extended high frequencies where stimulus calibrations and responses are most susceptible to the effect of standing waves. Behavioral thresholds and DPOAE amplitudes were negatively correlated, and DPOAE amplitudes in emitted pressure level accounted for twice as much variance as amplitudes in conventional sound pressure level units. Both measures were correlated with age. These data show that extended high-frequency DPOAEs are sensitive to differences in audiometric thresholds and highlight the need to consider calibration techniques in clinical and research applications of DPOAEs.

Early signs of auditory aging: Hearing declines faster in individuals with extended high frequency hearing loss

Hearing loss, particularly age-related hearing loss, significantly impacts health and quality of life worldwide. While much of the research has focused on older adults, the early stages of hearing decline remain relatively unexplored. Longitudinal studies examining hearing changes across the adult lifespan, especially at extended high frequencies (EHFs), are scarce. This prospective longitudinal study aimed to explore the rate of hearing threshold shift in young adults with clinically normal audiograms and to assess whether EHF hearing loss could predict future hearing decline in the standard audiometric range. Hearing thresholds were measured at standard audiometric frequencies (0.25 to 8 kHz) and EHFs (10, 12.5, 14, and 16 kHz) in 71 participants (24 females) aged 19 to 38 years (mean age = 27.8 years). Two testing sessions were conducted nearly 24 months apart. Results revealed that the annual rate of threshold shift was significantly higher for EHFs compared to standard audiometric frequencies. A higher EHF threshold, measured in the initial test session, was associated with a greater rate of threshold shift at standard audiometric frequencies, suggesting that EHF hearing loss may serve as an early marker for subsequent hearing decline. Even with a normal audiogram, individuals with EHF hearing loss are at an increased risk of accelerated hearing deterioration. These findings show preclinical, age-related changes in young adults with normal audiograms and underscore the importance of early detection and monitoring of EHF hearing loss to mitigate the impact of future hearing loss on their overall health and well-being.

Investigating the Potential Hearing Impairment and Ototoxicity in Children up to Six Years With Cystic Fibrosis After Aminoglycoside Exposure (PIANO-CF Extension)

BACKGROUND

People with CF (pwCF) are often treated with prolonged courses of aminoglycosides (AGs), for which known adverse effects include ototoxicity as a subset of hearing impairment (HI).

METHODS

The PIANO-CF trial was a single-center study conducted at The Royal Children's Hospital where 28 pediatric patients aged < 7 years underwent sequential hearing tests at increased range up to 12,500 Hz in relation to receiving intravenous (IV) AGs. More than 85% of the cohort (n = 24) participated in the follow-up hearing testing up to 1 year.

RESULTS

HI was defined by degree (dB) and frequency (Hz) on the audiogram. This was further reviewed to determine if the type of HI was consistent with ototoxicity as there are frequently other causes of HI in this age group. At baseline the prevalence of HI and ototoxicity were 11% and 7%, respectively. Over a period of 1 year, HI was identified in 12.5% and that of ototoxicity in 6%. No correlation was found between degree of IV AG exposure and HI or ototoxicity.

DISCUSSION

The finding of HI in young children with CF, including in those with minimal IV AG exposure, has implications for CF services to proactively screen for HI. Undetected HI may compromise learning outcomes and given the age of children studied, this is not insignificant during the acquisition and development of language skills.

CONCLUSION

Routine audiometric testing for pwCF up to 12,500 Hz or beyond may increase sensitivity in detection of ototoxicity and should be considered for use in screening, monitoring, and future research.

Extended high-frequency hearing loss among Afro-Colombian adolescents from a rural area in Colombia: a cross-sectional study

OBJECTIVES

Research trends concerning hearing loss within teen rural populations are limited and current evidence suggests that extended high-frequency audiometry can be a sensitive tool to detect subclinical hearing loss. Moreover, current research emphasises the importance of representing different ethnic populations in science. This study aimed to determine the prevalence of acquired hearing loss through conventional pure-tone (0.25-8 kHz) and extended high frequency (EHF) (9-20 kHz) audiometry in Afro-Colombian adolescents from a rural area in Colombia.

DESIGN

Observational, cross-sectional study.

PARTICIPANTS

230 Afro-Colombian adolescents aged 13-17 years who attended high school in a rural population from Cartagena, Colombia.

INTERVENTIONS

Otoscopic examination, conventional (0.25-8 kHz) and EHF (9-20 kHz) audiometry tests were performed during February-March 2021. Sociodemographic and associated factor questionnaires were also applied to assess probable factors associated with EHF hearing loss.

MAIN OUTCOME MEASURES

Prevalence of acquired hearing loss using conventional and EHF audiometry, and factors associated with hearing loss.

RESULTS

Of 230 adolescents who met the eligibility criteria, 133 (57.82%) were female. The mean age was 15.22 years (SD: 1.62). The prevalence of hearing loss in at least one ear assessed with conventional audiometry was 21.30% and with EHF audiometry 14.78%. The main abnormal otoscopic findings included: neotympanum (1.30%), myringosclerosis (0.87%) and monomeric scars (0.43%). Factors associated with a higher probability of EHF hearing loss found through logistic regression were older age (prevalence ratio (PR): 1.45; 95% CI 1.16 to 1.80), attending the 'Picó' four or more times a month (PR: 6.63; 95% CI 2.16 to 20.30), attending bars more than three times a month (PR: 1.14; 95% CI 1.03 to 1.59) and self-reported hearing difficulties (PR: 1.24; 95% CI 1.22 to 4.05).

CONCLUSIONS

Our results suggest that acquired hearing loss is already widespread among this young rural population.

The relationship between distortion product otoacoustic emissions and audiometric thresholds in the extended high-frequency range

Distortion product otoacoustic emissions (DPOAEs) and behavioral audiometry are routinely used for hearing screening and assessment. These measures provide related information about hearing status as both are sensitive to cochlear pathologies. However, DPOAE testing is quicker and does not require a behavioral response. Despite these practical advantages, DPOAE testing is often limited to screening only low and mid- frequencies. Variation in ear canal acoustics across ears and probe placements has resulted in less reliable measurements of DPOAEs near 4 kHz and above where standing waves commonly occur. Stimulus calibration in forward pressure level and responses in emitted pressure level can reduce measurement variability. Using these calibrations, this study assessed the correlation between audiometry and DPOAEs in the extended high frequencies where stimulus calibrations and responses are most susceptible to the effect of standing waves. Behavioral thresholds and DPOAE amplitudes were negatively correlated, and DPOAE amplitudes in emitted pressure level accounted for twice as much variance as amplitudes in sound pressure level. Both measures were correlated with age. These data show that with appropriate calibration methods, extended high-frequency DPOAEs are sensitive to differences in audiometric thresholds and highlight the need to consider calibration techniques in clinical and research applications of DPOAEs.

Exploring the Influence of Extended High-Frequency Hearing on Cochlear Functioning at Lower Frequencies

PURPOSE

Diminished basal cochlear function, as indicated by elevated hearing thresholds in the extended high frequencies (EHFs), has been associated with lower levels of click-evoked and distortion-product otoacoustic emissions measured at lower frequencies. However, stimulus-frequency otoacoustic emissions (SFOAEs) at low-probe levels are reflection-source emissions that do not share the same generation mechanism as distortion-source emissions. The primary objective of the present study was to examine the influence of hearing thresholds in the EHFs on SFOAEs measured at lower frequencies.

METHOD

SFOAEs were recorded from both ears in 45 individuals with normal hearing thresholds in the conventional audiometric frequencies (0.25-8 kHz). Hearing thresholds were also measured at EHFs (10, 12.5, and 16 kHz). SFOAE magnitudes and signal-to-noise ratios (SNRs) were averaged across 1, 2, and 4 kHz probe frequencies and also averaged for high-probe frequencies (2 and 4 kHz).

RESULTS

SFOAE magnitudes and SNRs were significantly higher for ears with better EHF hearing relative to poorer EHF hearing, categorized based on the median split. In addition, hearing in the EHFs significantly contributed to the variance in all SFOAE measures, except for the high-frequency SFOAE magnitudes model. However, hearing thresholds at the probe frequencies did not significantly contribute to the variance in SFOAEs.

CONCLUSIONS

The study findings suggest that alterations in the basal cochlea, as revealed by EHF hearing thresholds, could be associated with diminished cochlear functioning in relatively apical regions, shown by SFOAEs at lower frequencies, in individuals with normal audiograms. These findings underscore the significance of considering EHF thresholds in audiological evaluations, as alterations in these frequencies may reflect broader cochlear health status.

Effects of Stimulus Type on 16-kHz Detection Thresholds

OBJECTIVES

Audiometric testing typically does not include frequencies above 8 kHz. However, recent research suggests that extended high-frequency (EHF) sensitivity could affect hearing in natural communication environments. Clinical assessment of hearing often employs pure tones and frequency-modulated (FM) tones interchangeably regardless of frequency. The present study was designed to evaluate how the stimulus chosen to measure EHF thresholds affects estimates of hearing sensitivity.

DESIGN

The first experiment used standard audiometric procedures to measure 8- and 16-kHz thresholds for 5- to 28-year olds with normal hearing in the standard audiometric range (250 to 8000 Hz). Stimuli were steady tones, pulsed tones, and FM tones. The second experiment tested 18- to 28-year olds with normal hearing in the standard audiometric range using psychophysical procedures to evaluate how changes in sensitivity as a function of frequency affect detection of stimuli that differ with respect to bandwidth, including bands of noise. Thresholds were measured using steady tones, pulsed tones, FM tones, narrow bands of noise, and one-third-octave bands of noise at a range of center frequencies in one ear.

RESULTS

In experiment 1, thresholds improved with increasing age at 8 kHz and worsened with increasing age at 16 kHz. Thresholds for individual participants were relatively similar for steady, pulsed, and FM tones at 8 kHz. At 16 kHz, mean thresholds were approximately 5 dB lower for FM tones than for steady or pulsed tones. This stimulus effect did not differ as a function of age. Experiment 2 replicated this greater stimulus effect at 16 kHz than at 8 kHz and showed that the slope of the audibility curve accounted for these effects.

CONCLUSIONS

Contrary to prior expectations, there was no evidence that the choice of stimulus type affected school-age children more than adults. For individual participants, audiometric thresholds at 16 kHz were as much as 20 dB lower for FM tones than for steady tones. Threshold differences across stimuli at 16 kHz were predicted by differences in audibility across frequency, which can vary markedly between listeners. These results highlight the importance of considering spectral width of the stimulus used to evaluate EHF thresholds.

Subcortical Auditory Processing and Speech Perception in Noise Among Individuals With and Without Extended High-Frequency Hearing Loss

PURPOSE

The significance of extended high-frequency (EHF) hearing (> 8 kHz) is not well understood so far. In this study, we aimed to understand the relationship between EHF hearing loss (EHFHL) and speech perception in noise (SPIN) and the associated physiological signatures using the speech-evoked frequency-following response (sFFR).

METHOD

Sixteen young adults with EHFHL and 16 age- and sex-matched individuals with normal hearing participated in the study. SPIN performance in right speech-right noise, left speech-left noise, and binaural listening conditions was evaluated using the Turkish Matrix Test. Additionally, subcortical auditory processing was assessed by recording sFFRs elicited by 40-ms /da/ stimuli.

RESULTS

Individuals with EHFHL demonstrated poorer SPIN performances in all listening conditions (p < .01). Longer latencies were observed in the V (onset) and O (offset) peaks in these individuals (p ≤ .01). However, only the V/A peak amplitude was found to be significantly reduced in individuals with EHFHL (p < .01).

CONCLUSIONS

Our findings highlight the importance of EHF hearing and suggest that EHF hearing should be considered among the key elements in SPIN. Individuals with EHFHL show a tendency toward weaker subcortical auditory processing, which likely contributes to their poorer SPIN performance. Thus, routine assessment of EHF hearing should be implemented in clinical settings, alongside the evaluation of standard audiometric frequencies (0.25-8 kHz).

Explainable machine learning reveals the relationship between hearing thresholds and speech-in-noise recognition in listeners with normal audiograms

Some individuals complain of listening-in-noise difficulty despite having a normal audiogram. In this study, machine learning is applied to examine the extent to which hearing thresholds can predict speech-in-noise recognition among normal-hearing individuals. The specific goals were to (1) compare the performance of one standard (GAM, generalized additive model) and four machine learning models (ANN, artificial neural network; DNN, deep neural network; RF, random forest; XGBoost; eXtreme gradient boosting), and (2) examine the relative contribution of individual audiometric frequencies and demographic variables in predicting speech-in-noise recognition. Archival data included thresholds (0.25-16 kHz) and speech recognition thresholds (SRTs) from listeners with clinically normal audiograms (n = 764 participants or 1528 ears; age, 4-38 years old). Among the machine learning models, XGBoost performed significantly better than other methods (mean absolute error; MAE = 1.62 dB). ANN and RF yielded similar performances (MAE = 1.68 and 1.67 dB, respectively), whereas, surprisingly, DNN showed relatively poorer performance (MAE = 1.94 dB). The MAE for GAM was 1.61 dB. SHapley Additive exPlanations revealed that age, thresholds at 16 kHz, 12.5 kHz, etc., on the order of importance, contributed to SRT. These results suggest the importance of hearing in the extended high frequencies for predicting speech-in-noise recognition in listeners with normal audiograms.

Suprathreshold auditory processes in listeners with normal audiograms but extended high-frequency hearing lossa)

Hearing loss in the extended high-frequency (EHF) range (>8 kHz) is widespread among young normal-hearing adults and could have perceptual consequences such as difficulty understanding speech in noise. However, it is unclear how EHF hearing loss might affect basic psychoacoustic processes. The hypothesis that EHF hearing loss is associated with poorer auditory resolution in the standard frequencies was tested. Temporal resolution was characterized by amplitude modulation detection thresholds (AMDTs), and spectral resolution was characterized by frequency change detection thresholds (FCDTs). AMDTs and FCDTs were measured in adults with or without EHF loss but with normal clinical audiograms. AMDTs were measured with 0.5- and 4-kHz carrier frequencies; similarly, FCDTs were measured for 0.5- and 4-kHz base frequencies. AMDTs were significantly higher with the 4 kHz than the 0.5 kHz carrier, but there was no significant effect of EHF loss. There was no significant effect of EHF loss on FCDTs at 0.5 kHz; however, FCDTs were significantly higher at 4 kHz for listeners with than without EHF loss. This suggests that some aspects of auditory resolution in the standard audiometric frequency range may be compromised in listeners with EHF hearing loss despite having a normal audiogram.

Brainstem auditory physiology in children with listening difficulties. Hear Res 2023;429:108705. [PMID: 36709582 PMCID: PMC10152893 DOI: 10.1016/j.heares.2023.108705]

Children who have listening difficulties (LiD) despite having normal audiometry are often diagnosed as having an auditory processing disorder. A lack of evidence regarding involvement of specific auditory mechanisms has limited development of effective treatments for these children. Here, we examined electrophysiologic evidence for brainstem pathway mechanisms in children with and without defined LiD. We undertook a prospective controlled study of 132 children aged 6-14 years with normal pure tone audiometry, grouped into LiD (n = 63) or Typically Developing (TD; n = 69) based on scores on the Evaluation of Children's Listening and Processing Skills (ECLiPS), a validated caregiver report. The groups were matched on age at test, sex, race, and ethnicity. Neither group had diagnoses of major neurologic disorder, intellectual disability, or brain injuries. Both groups received a test battery including a measure of receptive speech perception against distractor speech, Listening in Spatialized Noise - Sentences (LiSN-S), along with multiple neurophysiologic measures that tap afferent and efferent auditory subcortical pathways. Group analysis showed that participants with LiD performed significantly poorer on all subtests of the LiSN-S. The LiD group had significantly greater wideband middle ear muscle reflex (MEMR) growth functions in the left ear, and shorter Wave III and Wave V latencies in auditory brainstem responses (ABR). Across individual participants, shorter latency ABR Wave V correlated significantly with poorer parent report of LiD (ECLiPS composite). Greater MEMR growth functions also correlated with poorer ECLiPS scores and reduced LiSN-S talker advantage. The LiD and TD groups had equivalent summating potentials, compound action potentials, envelope-following responses, and binaurally activated medial olivocochlear reflexes. In conclusion, there was no evidence for auditory synaptopathy for LiD. Evidence for brainstem differences in the LiD group was interpreted as increased central gain, with shorter ABR Wave III and V latencies and steeper MEMR growth curves. These differences were related to poorer parent report and speech perception in competing speech ability.

Characterization and Clinical Use of Bone Conduction Transducers at Extended High Frequencies

Measurement of bone conduction (BC) hearing thresholds at extended high frequencies (EHF; above 8 kHz) is of clinical interest but is technically complicated by limitations in standard BC transducer output, a lack of calibration standards and sparse clinical data from human subjects. A recently described calibration scheme using an artificial mastoid and interposed accelerometer is applied in this study to characterize and compare acceleration and computed force outputs over the 4-20 kHz range of two standard BC transducers: the RadioEar® B71 and B81, as well as two non-standard, commercially available BC transducers: the Tascam® HP-F200 and the Aftershokz® AS400. Measures of linear output growth, harmonic distortion and acoustic radiation are assessed and compared across devices. A maximum linear input voltage is established for each BC transducer using measurements of linear output growth and total harmonic distortion. At maximum linear input level, the Tascam shows superior force output by 25 to 40 dB above 8 kHz and the widest dynamic EHF range. Acoustic radiation per output force was lowest for the Tascam, whereas the AS400 behaved more like an air conduction earphone than a force generator. In a cohort of 15 normal hearing volunteers, BC thresholds, measured with the Tascam and reported in dB re 1 rms μN, were consistent with historical measures of EHF BC thresholds in similar subjects using an alternative BC transducer.

Noise-induced hearing disorders: Clinical and investigational tools

A series of articles discussing advanced diagnostics that can be used to assess noise injury and associated noise-induced hearing disorders (NIHD) was developed under the umbrella of the United States Department of Defense Hearing Center of Excellence Pharmaceutical Interventions for Hearing Loss working group. The overarching goals of the current series were to provide insight into (1) well-established and more recently developed metrics that are sensitive for detection of cochlear pathology or diagnosis of NIHD, and (2) the tools that are available for characterizing individual noise hazard as personal exposure will vary based on distance to the sound source and placement of hearing protection devices. In addition to discussing the utility of advanced diagnostics in patient care settings, the current articles discuss the selection of outcomes and end points that can be considered for use in clinical trials investigating hearing loss prevention and hearing rehabilitation.