Einseitige Taubheit und Cochlear-implant-Versorgung

[Speech discrimination with separated signal sources and sound localization with speech stimuli : Learning effects and reproducibility]

BACKGROUND

Binaural hearing enables better speech comprehension in noisy environments and is necessary for acoustic spatial orientation. This study investigates speech discrimination in noise with separated signal sources and measures sound localization. The aim was to study characteristics and reproducibility of two selected measurement techniques which seem to be suitable for description of the aforementioned aspects of binaural hearing.

MATERIALS AND METHODS

Speech reception thresholds (SRT) in noise and test-retest reliability were collected from 55 normal-hearing adults for a spatial setup of loudspeakers with angles of ± 45° and ± 90° using the Oldenburg sentence test. The investigations of sound localization were conducted in a semicircle and fullcircle setup (7 and 12 equidistant loudspeakers).

RESULTS

SRT (S-45N45: -14.1 dB SNR; S45N-45: -16.4 dB SNR; S0N90: -13.1 dB SNR; S0N-90: -13.4 dB SNR) and test-retest reliability (4 to 6 dB SNR) were collected for speech intelligibility in noise with separated signals. The procedural learning effect for this setup could only be mitigated with 120 training sentences. Significantly smaller SRT values, resulting in better speech discrimination, were found for the test situation of the right compared to the left ear. RMS values could be gathered for sound localization in the semicircle (1,9°) as well as in the fullcircle setup (11,1°). Better results were obtained in the retest of the fullcircle setup.

CONCLUSION

When using the Oldenburg sentence test in noise with spatially separated signals, it is mandatory to perform a training session of 120 sentences in order to minimize the procedural learning effect. Ear-specific SRT values for speech discrimination in noise with separated signal sources are required, which is probably due to the right-ear advantage. A training is recommended for sound localization in the fullcircle setup.

Long-Term Outcome of Cochlear Implantation in Children With Congenital, Perilingual, and Postlingual Single-Sided Deafness

OBJECTIVES

We investigated the long-term outcomes of children with single-sided deafness (SSD) after cochlear implant (CI) surgery, during and after rehabilitation, and compared the results of children with congenital, perilingual, and postlingual SSD. We evaluated the impact of SSD at age at onset and duration of deafness on their performance.

DESIGN

Thirty-six children with SSD treated with CI participated in the study: 20 had congenital, seven perilingual (defined: >0 to 4 years), and nine had postlingual deafness (defined as >4 years of age). Their outcome with CI were measured on both subjective and objective scales: duration of device use, speech intelligibility in noise and in quiet, bilateral hearing and localization ability, quality of life and hearing, presence and loudness of tinnitus, and hearing ability of the better hearing ear.

RESULTS

After a mean follow-up time of 4.75 years, 32 of the 36 children used their CI on a regular basis. The remaining four children were nonusers. These children had congenital SSD and were older than three years at the time of CI surgery. Overall, for congenital/perilingual and postlingual SSD, speech intelligibility in noise and the Speech, Spatial and Qualities of Hearing Scale (SSQ) speech subscore were significantly improved, as were their subjective and objective localization ability and hearing-related quality of life. Children with postlingual SSD benefited from the CI with regard to speech intelligibility, SSQ speech/spatial/total score, and localization error, and children with congenital SSD showed better results with a short duration of deafness of less than 3 years compared with those with a longer deafness period.

CONCLUSIONS

Cochlear implantation is a successful treatment for children with congenital/perilingual or postlingual SSD. Results largely differed with respect to the onset and duration of deafness, and better outcomes were achieved by children with postlingual SSD and with a short duration of deafness. Our data also confirmed that children with congenital SSD should be implanted with a CI within three years of age.

[Prospective comparative analysis of cochlear implant patients with single-sided deafness and asymmetric hearing loss with regard to health-related quality of life, tinnitus distress and psychological comorbidities]

BACKGROUND

Patients with single-sided deafness (SSD) and asymmetric hearing loss (AHL) are increasingly being treated with cochlear implants (CI) due to the demonstrated improvements in auditory abilities and quality of life. To date, there are few published studies in which these two groups are comparatively studied. The aim of the current study was to examine which factors differ between those two patient groups, especially preoperatively.

METHODS

A secondary analysis of the previously published raw data of 66 prospectively recruited CI patients (21 SSD/45 AHL) was performed. In addition to the hearing outcome, tinnitus distress (tinnitus questionnaire), health-related quality of life (Nijmegen Cochlear Implant Questionnaire, NCIQ), stress (Perceived Stress Questionnaire, PSQ), and psychological comorbidities (General Depression Scale, ADS‑L and Generalized Anxiety Disorder scale, GAD-7) were assessed in SSD and AHL patients pre- and postoperatively.

RESULTS

Preoperatively, SSD patients showed significantly higher scores in the NCIQ subdomains "elementary" and "advanced sound perception" than the AHL group. Stress (PSQ) and anxiety symptoms (GAD-7) were significantly higher preoperatively in SSD patients than in AHL patients. After CI, these differences were strongly reduced, with minimal differences being detectable between the groups in the investigated domains postoperatively.

CONCLUSION

SSD and AHL patients differ significantly preoperatively in terms of their subjective hearing assessment and psychosocial parameters. In SSD patients, psychological stress factors may have a stronger impact on the quality of life than in AHL patients. These aspects should be taken into account in the preoperative counseling and postoperative rehabilitation.

Extended Preoperative Audiometry for Outcome Prediction and Risk Analysis in Patients Receiving Cochlear Implants

BACKGROUND

The outcome of cochlear implantation has improved over the last decades, but there are still patients with less benefit. Despite numerous studies examining the cochlear implant (CI) outcome, variations in speech comprehension with CI remains incompletely explained. The aim of this study was therefore to examine preoperative pure-tone audiogram and speech comprehension as well as aetiology, to investigate their relationship with postoperative speech comprehension in CI recipients.

METHODS

A retrospective study with 664 ears of 530 adult patients was conducted. Correlations between the target variable postoperative word comprehension with the preoperative speech and sound comprehension as well as aetiology were investigated. Significant correlations were inserted into multivariate models. Speech comprehension measured as word recognition score at 70 dB with CI was analyzed as (i) a continuous and (ii) a dichotomous variable.

RESULTS

All variables that tested preoperative hearing were significantly correlated with the dichotomous target; with the continuous target, all except word comprehension at 65 dB with hearing aid. The strongest correlation with postoperative speech comprehension was seen for monosyllabic words with hearing aid at 80 dB. The preoperative maximum word comprehension was reached or surpassed by 97.3% of CI patients. Meningitis and congenital diseases were strongly negatively associated with postoperative word comprehension. The multivariate model was able to explain 40% of postoperative variability.

CONCLUSION

Speech comprehension with hearing aid at 80 dB can be used as a supplementary preoperative indicator of CI-aided speech comprehension and should be measured regularly in the clinical routine. Combining audiological and aetiological variables provides more insights into the variability of the CI outcome, allowing for better patient counselling.

Auditory cortical plasticity after cochlear implantation in asymmetric hearing loss is related to spatial hearing: a PET H215O study

In asymmetric hearing loss (AHL), the normal pattern of contralateral hemispheric dominance for monaural stimulation is modified, with a shift towards the hemisphere ipsilateral to the better ear. The extent of this shift has been shown to relate to sound localization deficits. In this study, we examined whether cochlear implantation to treat postlingual AHL can restore the normal functional pattern of auditory cortical activity and whether this relates to improved sound localization. The auditory cortical activity was found to be lower in the AHL cochlear implanted (AHL-CI) participants. A cortical asymmetry index was calculated and showed that a normal contralateral dominance was restored in the AHL-CI patients for the nonimplanted ear, but not for the ear with the cochlear implant. It was found that the contralateral dominance for the nonimplanted ear strongly correlated with sound localization performance (rho = 0.8, P < 0.05). We conclude that the reorganization of binaural mechanisms in AHL-CI subjects reverses the abnormal lateralization pattern induced by the deafness, and that this leads to improved spatial hearing. Our results suggest that cochlear implantation enables the reconstruction of the cortical mechanisms of spatial selectivity needed for sound localization.

Cochlear implantation in patients with asymmetric hearing loss: reporting and discussing the benefits in speech perception, speech reception threshold, squelch abilities, and patients’ reported outcomes

Objectives

This study presents the results obtained in a group of patients with asymmetric hearing loss undergoing cochlear implantation at our institution. Prognostic factors are discussed in relation to different rehabilitative approaches for asymmetric hearing loss remediation. The current literature is also discussed.

Methods

Nineteen adult patients with post-verbal asymmetric hearing loss were enrolled. The results were assessed by means of a speech perception test, completed in silence and with background noise, and a speech reception threshold test (Oldenburg Sentence Test). The subjectively perceived benefits were assessed using the Speech, Spatial and Qualities of Hearing Scale.

Results

Statistically significant improvements were achieved by all patients in terms of speech perception and speech reception threshold, and in subjective benefits.

Conclusion

The results confirm the literature findings which suggest that patients with asymmetric hearing loss generally gain substantial benefit from cochlear implantation because of the binaural input, with significant improvement in speech perception abilities in noise, speech reception threshold, and squelch abilities.

Side-of-Implantation Effect on Functional Asymmetry in the Auditory Cortex of Single-Sided Deaf Cochlear-Implant Users

Cochlear implants (CIs) allow to restore the hearing function in profoundly deaf individuals. Due to the degradation of the stimulus by CI signal processing, implanted individuals with single-sided deafness (SSD) have the specific challenge that the input highly differs between their ears. The present study compared normal-hearing (NH) listeners (N = 10) and left- and right-ear implanted SSD CI users (N = 10 left, N = 9 right), to evaluate cortical speech processing between CI- and NH-ears and to explore for side-of-implantation effects. The participants performed a two-deviant oddball task, separately with the left and the right ear. Auditory event-related potentials (ERPs) in response to syllables were compared between proficient and non-proficient CI users, as well as between CI and NH ears. The effect of the side of implantation was analysed on the sensor and the source level. CI proficiency could be distinguished based on the ERP amplitudes of the N1 and the P3b. Moreover, syllable processing via the CI ear, when compared to the NH ear, resulted in attenuated and delayed ERPs. In addition, the left-ear implanted SSD CI users revealed an enhanced functional asymmetry in the auditory cortex than right-ear implanted SSD CI users, regardless of whether the syllables were perceived via the CI or the NH ear. Our findings reveal that speech-discrimination proficiency in SSD CI users can be assessed by N1 and P3b ERPs. The results contribute to a better understanding of the rehabilitation success in SSD CI users by showing that cortical speech processing in SSD CI users is affected by CI-related stimulus degradation and experience-related functional changes in the auditory cortex.

Neural activity of the auditory cortex predicts speech recognition of patients with asymmetric hearing loss after cochlear implantation

Patients with asymmetric hearing loss show an asymmetry of glucose metabolism of the primary auditory cortex (PAC). We investigated whether this asymmetry could serve as an objective predictor for speech recognition with CI. Nine patients underwent ¹⁸FDG PET prior to CI surgery. Average normalized ¹⁸FDG uptake of 25% of voxels with highest uptake was calculated for the PAC employing a probabilistic atlas and cerebellar cortex as reference. Differences in glucose metabolism of the PAC were assessed by an asymmetry index (AI-PAC). We tested the correlation between outcome of CI surgery (6 months post implantation), AI-PAC and clinical predictors. Pre-operative AI-PAC showed a positive correlation with speech recognition with CI (significant for sentences and numbers; trend for monosyllabic words). With a pre-operative AI-PAC ≥ 4.2%, patients reached good CI outcome in sentence recognition of 59–90% and number recognition of 90–100% and less favorable CI outcome in monosyllabic word recognition of 25–45%. Age at symptom onset was significantly associated with all measures of speech recognition, while deafness duration was only associated with sentence recognition. AI-PAC allows for a reliable and quantitative pre-operative prediction of early improvement in speech recognition after CI. ¹⁸FDG PET may be a valuable addition to the objective pre-operative assessment of CI candidates. Further studies in larger cohorts and with longer follow-up times are needed.

Patient Sentiments Influencing Management Strategy for Single-sided Deafness

OBJECTIVE

Assess opinions that influence treatment choice for single sided deafness (SSD).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary neurotology referral center.

PATIENTS

Patients with SSD were recruited between December 2020 and February 2021. Included patients were self-selected by voluntary completion of the study questionnaire.

MAIN OUTCOME MEASURES

Tinnitus Handicap Inventory (THI), Hearing Handicap Inventory for Adults (HHIA), and a questionnaire containing 25 areas of inquiry relevant to management strategy decision making.

RESULTS

In comparison to the surgical management group, patients opting for nonsurgical amplification were significantly more concerned about device visibility (p = 0.005, 1.32 ± 0.22 versus 2.67 ± 0.37), undergoing surgery (p = 0.017, 1.64 ± 0.23 versus 2.89 ± 0.51), and the thought of harboring an implanted device (p = 0.003, 1.46 ± 0.22 versus 2.82 ± 0.35). Patients with a major hearing handicap (grade 2-4) placed significantly less emphasis on out-of-pocket costs (p = 0.049, 2.38 ± 0.17 versus 2.94 ± 0.21) and were less concerned about experiencing discomfort from the device (p = 0.033, 3.13 ± 0.11 versus 3.56 ± 0.16) or ease of device use (p = 0.040, 3.20 ± 0.13 versus 3.63 ± 0.13) when compared with the minor handicap group.

CONCLUSIONS

Lingering concerns about device visibility, undergoing surgery, and harboring an implanted device underscore the need for thorough patient counseling during SSD device selection consultations. These efforts should aim to address esthetic and surgical risk concerns while emphasizing the potential for improvements in quality of life.

Systematic review of outcome domains and instruments used in designs of clinical trials for interventions that seek to restore bilateral and binaural hearing in adults with unilateral severe to profound sensorineural hearing loss ('single-sided deafness')

BACKGROUND

This systematic review aimed to identify, compare and contrast outcome domains and outcome instruments reported in studies investigating interventions that seek to restore bilateral (two-sided) and/or binaural (both ears) hearing in adults with single-sided deafness (SSD). Findings can inform the development of evidence-based guidance to facilitate design decisions for confirmatory trials.

METHODS

Records were identified by searching MEDLINE, EMBASE, PubMed, CINAHL, ClinicalTrials.gov, ISRCTN, CENTRAL, WHO ICTRP and the NIHR UK clinical trials gateway. The search included records published from 1946 to March 2020. Included studies were those as follows: (a) recruiting adults aged 18 years or older diagnosed with SSD of average threshold severity worse than 70 dB HL in the worse-hearing ear and normal (or near-normal) hearing in the better-hearing ear, (b) evaluating interventions to restore bilateral and/or binaural hearing and (c) enrolling those adults in a controlled trial, before-and-after study or cross-over study. Studies that fell just short of the participant eligibility criteria were included in a separate sensitivity analysis.

RESULTS

Ninety-six studies were included (72 full inclusion, 24 sensitivity analysis). For fully included studies, 37 exclusively evaluated interventions to re-establish bilateral hearing and 29 exclusively evaluated interventions to restore binaural hearing. Overall, 520 outcome domains were identified (350 primary and 170 secondary). Speech-related outcome domains were the most common (74% of studies), followed by spatial-related domains (60% of studies). A total of 344 unique outcome instruments were reported. Speech-related outcome domains were measured by 73 different instruments and spatial-related domains by 43 different instruments. There was considerable variability in duration of follow-up, ranging from acute (baseline) testing to 10 years after the intervention. The sensitivity analysis identified no additional outcome domains.

CONCLUSIONS

This review identified large variability in the reporting of outcome domains and instruments in studies evaluating the therapeutic benefits and harms of SSD interventions. Reports frequently omitted information on what domains the study intended to assess, and on what instruments were used to measure which domains.

TRIAL REGISTRATION

The systematic review protocol is registered on PROSPERO (International Prospective Register of Systematic Reviews): Registration Number CRD42018084274 . Registered on 13 March 2018, last revised on 7th of May 2019.

Bone-anchored hearing system, contralateral routing of signals hearing aid or cochlear implant: what is best in single-sided deafness?

PURPOSE

The aim of the study was to compare long-term results after 1 year in patients with single-sided deafness (SSD) who were fitted with different hearing aids. The participants tested contralateral routing of signals (CROS) hearing aids and bone-anchored hearing systems (BAHS). They were also informed about the possibility of a cochlear implant (CI) and chose one of the three devices. We also investigated which factors influenced the choice of device.

METHODS

Prospective study with 89 SSD participants who were divided into three groups by choosing BAHS, CROS, or CI. All participants received test batteries with both objective hearing tests (speech perception in noise and sound localisation) and subjective questionnaires.

RESULTS

16 participants opted for BAHS-, 13 for CROS- and 30 for CI-treatment. The greater the subjective impairment caused by SSD, the more likely patients were to opt for surgical treatment (BAHS or CI). The best results in terms of speech perception in noise (especially when sound reaches the deaf ear and noise the hearing ear), sound localization, and subjective results were achieved with CI.

CONCLUSION

The best results regarding the therapy of SSD are achieved with a CI, followed by BAHS. This was evident both in objective tests and in the subjective questionnaires. Nevertheless, an individual decision is required in each case as to which SSD therapy option is best for the patient. Above all, the patient's subjective impairment and expectations should be included in the decision-making process.

Management of transmodiolar and transmacular cochleovestibular schwannomas with and without cochlear implantation

Introduction

Hearing rehabilitation with cochlear implants has attracted increasing interest also for patients with cochleovestibular schwannoma. The authors report their experience with the surgical management of tumors with rare transmodiolar or transmacular extension and outcomes after cochlear implantation (CI).

Methods

This retrospective case series included nine patients with either primary intralabyrinthine tumors or secondary invasion of the inner ear from the internal auditory canal. The primary endpoint with CI, performed in six patients, was word recognition score at 65 dB SPL (sound pressure level). Secondary endpoints were intra- and postoperative electrophysiological parameters, impedance measures, the presence of a wave V in the electrically evoked (via the CI) auditory brainstem responses, the specifics of postoperative CI programming, and adverse events.

Results

Hearing rehabilitation with CI in cases of transmodiolar tumor growth could be achieved only with incomplete tumor removal, whereas tumors with transmacular growth could be completely removed. All six patients with CI had good word recognition scores for numbers in quiet conditions (80–100% at 65 dB SPL, not later than 6 to 12 months post CI activation). Four of these six patients achieved good to very good results for monosyllabic words within 1–36 months (65–85% at 65 dB SPL). The two other patients, however, had low scores for monosyllables at 6 months (25 and 15% at 65 dB SPL, respectively) with worsening of results thereafter.

Conclusions

Cochleovestibular schwannomas with transmodiolar and transmacular extension represent a rare entity with specific management requirements. Hearing rehabilitation with CI is a principal option in these patients.

Video online

The online version of this article (10.1007/s00106-020-00919-9) includes a video (2D and 3D versions) of the described surgical technique. Article and supplementary material are available at www.springermedizin.de. Please enter the title of the article in the search field, the supplementary material can be found under “Ergänzende Inhalte”.

Is the cochlear implant a successful long-term solution for single-sided deaf and asymmetric hearing-impaired patients?

PURPOSE

We investigated the long-term results of cochlear implant (CI) recipients with asymmetric hearing loss (AHL) or single-sided deafness (SSD). We focused on wearing behavior, audiometric hearing rehabilitation, and subjective benefits of the CI. CI is expected to improve audiological results, subjective hearing perception, and tinnitus burden.

METHODS

Speech recognition in background noise and sound localization were assessed preoperatively and after at least six years of CI experience. Validated questionnaires determined the subjective benefit of CI use and the subjective evaluation of tinnitus.

RESULTS

Over 80% of the included AHL and SSD CI recipients used their CI between 6 and 10 h daily; four subjects with SSD were non-users. Speech recognition in background noise and sound localization improved significantly compared with the unaided preoperative situation. Additionally, CI improved subjective speech intelligibility and spatial hearing impression while reducing tinnitus burden.

CONCLUSION

Subjects with AHL and SSD benefit from CI, subjectively and audiologically. Cochlear implant is a successful long-term treatment for AHL and SSD.

[Management of transmodiolar and transmacular cochleovestibular schwannomas with and without cochlear implantation. German version]

INTRODUCTION

Hearing rehabilitation with cochlear implants has attracted increasing interest also for patients with cochleovestibular schwannoma. The authors report their experience with the surgical management of tumors with rare transmodiolar or transmacular extension and outcomes after cochlear implantation (CI).

METHODS

This retrospective case series included nine patients with either primary intralabyrinthine tumors or secondary invasion of the inner ear from the internal auditory canal. The primary endpoint with CI, performed in six patients, was word recognition score at 65 dB SPL (sound pressure level). Secondary endpoints were intra- and postoperative electrophysiological parameters, impedance measures, the presence of a wave V in the electrically evoked (via the CI) auditory brainstem responses, the specifics of postoperative CI programming, and adverse events.

RESULTS

Hearing rehabilitation with CI in cases of transmodiolar tumor growth could be achieved only with incomplete tumor removal, whereas tumors with transmacular growth could be completely removed. All six patients with CI had good word recognition scores for numbers in quiet conditions (80-100% at 65 dB SPL, not later than 6 to 12 months post CI activation). Four of these six patients achieved good to very good results for monosyllabic words within 1-36 months (65-85% at 65 dB SPL). The two other patients, however, had low scores for monosyllables at 6 months (25 and 15% at 65 dB SPL, respectively) with worsening of results thereafter.

CONCLUSIONS

Cochleovestibular schwannomas with transmodiolar and transmacular extension represent a rare entity with specific management requirements. Hearing rehabilitation with CI is a principal option in these patients.

Cochlear Implantation in Patients With Single-sided Deafness After the Translabyrinthine Resection of the Vestibular Schwannoma-Presented at the Annual Meeting of ADANO 2016 in Berlin

OBJECTIVE

To evaluate effectiveness of the cochlear implant (CI) to facilitate single-sided deafness (SSD) rehabilitation following translabyrinthine resection of the vestibular schwannoma.

STUDY DESIGN

Retrospective patient review.

SETTING

Single center, University hospital.

PATIENTS

Patients with SSD who underwent translabyrinthine resection of a vestibular schwannoma with anatomical preservation of the cochlear nerve and subsequent CI on the same ear.

INTERVENTIONS

CI at post-translabyrinthine resection of the acoustic neuroma to treat SSD, and evaluation by retrospective individual case review in a period from 2009 to 2016.

MAIN OUTCOME MEASURES

Individual patients' clinical outcome and speech understanding.

RESULTS

Thirteen patients were provided CI. In all cases, complete removal of the tumor was achieved and the cochlear nerve was preserved; in one case, the CI was implanted simultaneously. In most cases, the follow-up interval was 2 years. In 9 of 13 cases, the implanted ear achieved capability to understand and discriminate monosyllabic words at 65 dB. Level of speech understanding of over 50% at 65 dB was possible in 7 patients at 12 months after the first fitting of CI.

CONCLUSIONS

Under certain conditions, CI was an effective solution to restore hearing in patients with SSD following translabyrinthine access to the skull base. Study with prospective design is required to provide more significant results.

Usefulness of cochlear implantation in children with single sided deafness

OBJECTIVES

Children with single sided deafness (SSD) show a poorer performance at school, which is attributable to reduced speech discrimination in noise, to reduced localization ability, and to a decreased power of concentration due to faster hearing exhaustion. Therefore, it is important to provide children with SSD with adequate hearing amplification to restore binaural hearing. This can only be achieved by provision with a cochlear implant (CI). But these treatment option in children with SSD is still under discussion. The aim of the present study is to evaluate audiological and clinical results in children with SSD following cochlear implantation. A special focus was placed on the duration of deafness before implantation and on the frequency of CI-use in everyday life.

METHODS

Seven children with SSD of different etiologies who were provided with a CI between 3 and 16 years of age were evaluated. Every child underwent multiple audiological tests before and after cochlear implantation. After cochlear implantation speech recognition tests in noise using the HSM (Hochmair, Schulz and Moser 1997) test and localization tests were performed. Furthermore, the frequency of implant use was evaluated.

RESULTS

Speech recognition in noise with CI compared to the unaided condition significantly improved in all children in different settings. Improvement of the localization ability measured by the root mean square error (RMSE) was shown in all children. All children are very satisfied with the decision to have undergone cochlear implantation and are all full-time users.

CONCLUSIONS

Cochlear implantation benefits speech recognition in noise and sound localization ability in children with SSD at different ages. All implanted children are full-time users regardless of age or duration of deafness before implantation.

[Cochlear implant treatment of patients with single-sided deafness or asymmetric hearing loss. German version]

BACKGROUND

The rehabilitation of patients with single-sided deafness (SSD) or asymmetric hearing loss can be achieved with conventional (bilateral) contralateral routing of signals ((Bi)CROS) hearing aids ((Bi)CROS-HA, (Bi)CROS), bone-anchored hearing systems (BAHS) or cochlear implants (CI). To date, only small case series have been published on treatment outcomes in SSD patients after CI surgery and there are only a few comparative studies evaluating rehabilitation outcomes.

OBJECTIVE

The aim of this study was to provide evidence of successful treatment of SSD and asymmetric hearing loss with a CI compared to the untreated monaural hearing condition and the BAHS and (Bi)CROS treatment options in a large number of patients.

MATERIALS AND METHODS

In a single-centre study, 45 patients with SSD and 40 patients with asymmetric hearing loss were treated with a CI after careful evaluation for CI candidacy. Monaural speech comprehension in noise and localisation ability were examined with (Bi)CROS-HA and BAHS devices (on a test rod) both preoperatively and at 12 months after CI switch-on. At the same intervals, subjective evaluation of hearing ability was conducted using the Speech, Spatial and Qualities of Hearing Scale (SSQ).

RESULTS

This report presents the first evidence of successful binaural rehabilitation with CI in a relatively large patient cohort and the advantages over (Bi)CROS and BAHS in smaller subgroups, thus confirming the indication for CI treatment. Moreover, patients with long-term acquired deafness (>10 years) show a benefit from the CI comparable to that observed in patients with shorter-term deafness.

Nonsurgical Management of Single-Sided Deafness: Contralateral Routing of Signal

In recent years, an increasing research effort has been directed toward remediation of single-sided deafness. Contralateral routing of signal (CROS) is the longest standing rehabilitation solution for individuals with single-sided deafness. The primary goal of CROS technology is to transfer the signal received at the deaf ear to the better hearing ear, thereby reducing the impact of the acoustic head-shadow. This allows for individuals with single-sided deafness to regain access to sounds located at the deaf ear. The hearing deficits associated with single-sided deafness are often debilitating. While surgical management of single-sided deafness is on the rise, CROS hearing aids offer a nonsurgical option to compensate for some of the deficits that occur when a listener is limited to a single ear. Limitations of early CROS devices resulted in poor adoption and acceptance in those with single-sided deafness. Following significant advances in both design and technology, the acceptance of CROS devices has increased in recent years. This paper reviews relevant literature in CROS application for the management of single-sided deafness. Technological advances, benefits, limitations, and clinical considerations are also reviewed in this article.

[Subjective improvement of hearing through cochlear implantation]

BACKGROUND

During the past few decades various questionnaires have been developed to evaluate quality of life using audiological measures. The Hearing Implant Sound Quality Index (HISQUI) was developed especially for patients with a cochlear implant (CI). The aim of this study was to evaluate subjective hearing improvement after CI surgery and to correlate the results with objective measuring methods such as pure-tone and speech audiometry.

MATERIALS AND METHODS

Pre- and postoperative data of 57 patients who received a cochlear implant (CIs) were retrospectively analyzed. For evaluation of subjective hearing ability the HISQUI questionnaire consisting of 19 questions was used as reference. Pure-tone audiometry and Freiburger monosyllable word tests were used as objective measurements for hearing.

RESULTS

The mean HISQUI score increased on average from 53.0 prior to surgery to 69.0 after surgery. In addition, there were significant improvements in all seven subgroups of the questionnaire divisions. A correlation of r_Sp = 0.53 before surgery and r_Sp = 0.36 after surgery between the HISQUI scores and Freiburg monosyllable word test was recorded. In addition the 4FPTA (four frequency pure tone average) value correlated negatively with r_Sp = -0.48 with the HISQUI total score before surgery.

CONCLUSION

The moderate correlation of both subjective and objective measurement methods underlines the importance of enquiring the patients' subjective perception and satisfaction. Through the combination of subjective statements and measurements of speech comprehension it is possible to obtain a comprehensive picture of the hearing performance of CI recipients.

Hearing Instruments for Unilateral Severe-to-Profound Sensorineural Hearing Loss in Adults: A Systematic Review and Meta-Analysis

Objectives:

A systematic review of the literature and meta-analysis was conducted to assess the nature and quality of the evidence for the use of hearing instruments in adults with a unilateral severe to profound sensorineural hearing loss.

Design:

The PubMed, EMBASE, MEDLINE, Cochrane, CINAHL, and DARE databases were searched with no restrictions on language. The search included articles from the start of each database until February 11, 2015. Studies were included that (a) assessed the impact of any form of hearing instrument, including devices that reroute signals between the ears or restore aspects of hearing to a deaf ear, in adults with a sensorineural severe to profound loss in one ear and normal or near-normal hearing in the other ear; (b) compared different devices or compared a device with placebo or the unaided condition; (c) measured outcomes in terms of speech perception, spatial listening, or quality of life; (d) were prospective controlled or observational studies. Studies that met prospectively defined criteria were subjected to random effects meta-analyses.

Results:

Twenty-seven studies reported in 30 articles were included. The evidence was graded as low-to-moderate quality having been obtained primarily from observational before-after comparisons. The meta-analysis identified statistically significant benefits to speech perception in noise for devices that rerouted the speech signals of interest from the worse ear to the better ear using either air or bone conduction (mean benefit, 2.5 dB). However, these devices also degraded speech understanding significantly and to a similar extent (mean deficit, 3.1 dB) when noise was rerouted to the better ear. Data on the effects of cochlear implantation on speech perception could not be pooled as the prospectively defined criteria for meta-analysis were not met. Inconsistency in the assessment of outcomes relating to sound localization also precluded the synthesis of evidence across studies. Evidence for the relative efficacy of different devices was sparse but a statistically significant advantage was observed for rerouting speech signals using abutment-mounted bone conduction devices when compared with outcomes after preoperative trials of air conduction devices when speech and noise were colocated (mean benefit, 1.5 dB). Patients reported significant improvements in hearing-related quality of life with both rerouting devices and following cochlear implantation. Only two studies measured health-related quality of life and findings were inconclusive.

Conclusions:

Devices that reroute sounds from an ear with a severe to profound hearing loss to an ear with minimal hearing loss may improve speech perception in noise when signals of interest are located toward the impaired ear. However, the same device may also degrade speech perception as all signals are rerouted indiscriminately, including noise. Although the restoration of functional hearing in both ears through cochlear implantation could be expected to provide benefits to speech perception, the inability to synthesize evidence across existing studies means that such a conclusion cannot yet be made. For the same reason, it remains unclear whether cochlear implantation can improve the ability to localize sounds despite restoring bilateral input. Prospective controlled studies that measure outcomes consistently and control for selection and observation biases are required to improve the quality of the evidence for the provision of hearing instruments to patients with unilateral deafness and to support any future recommendations for the clinical management of these patients.

Adults with a unilateral severe-to-profound sensorineural hearing loss report difficulties with listening in many everyday situations. Current hearing instruments attempt to alleviate these difficulties either by rerouting sounds from the impaired ear to the non-impaired ear or by restoring hearing in the impaired ear. A systematic review and meta-analysis evaluated the evidence for their use. The evidence was of low-to-moderate quality. Meta-analyses found benefits to speech perception in noise and reductions in listening difficulty. Controlled trials are needed to provide higher-quality evidence for hearing instrument use in unilateral deafness and to support recommendations for the clinical management of these patients.

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Hearing aids: indications, technology, adaptation, and quality control

Hearing loss can be caused by a number of different pathological conditions. Some of them can be successfully treated, mainly by surgery, depending on the individual's disease process. However, the treatment of chronic sensorineural hearing loss with damaged cochlear structures usually needs hearing rehabilitation by means of technical amplification. During the last two decades tremendous improvements in hearing aid technology led to a higher quality of the hearing rehabilitation process. For example, due to sophisticated signal processing acoustic feedback could be reduced and hence open fitting options are available even for more subjects with higher degrees of hearing loss. In particular for high-frequency hearing loss, the use of open fitting is an option. Both the users' acceptance and the perceived sound quality were significantly increased by open fittings. However, we are still faced with a low level of readiness in many hearing impaired subjects to accept acoustic amplification. Since ENT specialists play a key-role in hearing aid provision, they should promote early hearing aid rehabilitation and include this in the counselling even in subjects with mild and moderate hearing loss. Recent investigations demonstrated the benefit of early hearing aid use in this group of patients since this may help to reduce subsequent damages as auditory deprivation, social isolation, development of dementia, and cognitive decline. For subjects with tinnitus, hearing aids may also support masking by environmental sounds and enhance cortical inhibition. The present paper describes the latest developments of hearing aid technology and the current state of the art for amplification modalities. Implications for both hearing aid indication and provision are discussed.

[Treatment and auditory rehabilitation of intralabyrinthine schwannoma by means of cochlear implants - German Version]

BACKGROUND

To date, the therapy of intralabyrinthine schwannoma consists mainly of a wait-and-see approach, completely ignoring auditory rehabilitation. Only a few single-case reports are as yet available on treatment with cochlear implants (CI).

AIM OF THE STUDY

This study aimed to assess the results of auditory rehabilitation after treatment with CI in a series of cases.

MATERIALS AND METHODS

The demographic findings, symptoms, and results of surgical therapy in 8 patients were evaluated in a retrospective analysis.

RESULTS

Prior to surgery, all patients presented with profound hearing loss and tinnitus. Episodic dizziness was reported by 3 patients. Among the patients, 4 had an intracochlear and 3 an intravestibular schwannoma, and a transmodiolar schwannoma was found in 1 patient. A total of 6 patients underwent treatment with CI. The results of auditory rehabilitation are favorable with open-set speech comprehension.

DISCUSSION

CI treatment following resection of an intralabyrinthine schwannoma is a promising option for auditory rehabilitation, even in single-sided deafness. This is a new treatment concept in contrast to the wait-and-scan policy. Expectant management appears justified only if the patient still has usable hearing.

[Speech audiometry for indication of conventional and implantable hearing aids]

The social function of the human hearing apparatus is comprehension of speech. Auditory rehabilitation aims to enhance speech perception in everyday life. Consequently, audiological evaluation contains speech perception measurement. Many speech audiometric methods have been developed in German-speaking countries, which are suitable for quantification of speech perception abilities in quiet and in noise to address specific diagnostic questions. For establishment of the indication for technical hearing systems such as hearing aids and cochlear implants, the Freiburg monosyllabic test has been employed successfully for many years. Particularly sentence tests have been suggested as a complementary measure for hearing aid indication and assessment. This paper describes the characteristics and range of application of various speech audiometric methods, and highlights the methodological limitations of the individual tests.

Functional Result After Cochlear Implantation in Children and Adults With Single-sided Deafness

BACKGROUND

Patients with single-sided deafness (SSD) suffer from reduced binaural hearing (i.e., sound localization and speech in noise discrimination). Cochlear implantation has recently been introduced for patients with SSD, as an alternative to hearing devices that employ contralateral routing of the signal. Application to children has also been started.

METHODS

We retrospectively analyze a case series of 4 children and 17 adults with SSD, treated with cochlear implantation. The outcome of adult patients was compared with a control group of 27 patients with bilateral profound hearing loss using a cochlear implant.

RESULTS

During 12 months, the mean speech recognition score increased from 30 to 41% for monosyllabic words in adults, and from 58 to 89% for multisyllabic numbers. The cochlear implant (CI) improved hearing in noise in all SSD patients, as was demonstrated by a significant improvement of the speech reception threshold in different speech and noise configurations. Sound localization-correlated angle detection error improved with CI use at every time point. The maximum word recognition score for monosyllabic words in quiet correlated with the logarithm of the duration of deafness; improvement of the speech reception threshold and RMS angle detection error by the CI did not.

CONCLUSION

All SSD patients benefitted from the CI in different hearing situations. Patients with SSD for a long period can improve after cochlear implantation.

Cross-modal plasticity in developmental and age-related hearing loss: Clinical implications

This review explores cross-modal cortical plasticity as a result of auditory deprivation in populations with hearing loss across the age spectrum, from development to adulthood. Cross-modal plasticity refers to the phenomenon when deprivation in one sensory modality (e.g. the auditory modality as in deafness or hearing loss) results in the recruitment of cortical resources of the deprived modality by intact sensory modalities (e.g. visual or somatosensory systems). We discuss recruitment of auditory cortical resources for visual and somatosensory processing in deafness and in lesser degrees of hearing loss. We describe developmental cross-modal re-organization in the context of congenital or pre-lingual deafness in childhood and in the context of adult-onset, age-related hearing loss, with a focus on how cross-modal plasticity relates to clinical outcomes. We provide both single-subject and group-level evidence of cross-modal re-organization by the visual and somatosensory systems in bilateral, congenital deafness, single-sided deafness, adults with early-stage, mild-moderate hearing loss, and individual adult and pediatric patients exhibit excellent and average speech perception with hearing aids and cochlear implants. We discuss a framework in which changes in cortical resource allocation secondary to hearing loss results in decreased intra-modal plasticity in auditory cortex, accompanied by increased cross-modal recruitment of auditory cortices by the other sensory systems, and simultaneous compensatory activation of frontal cortices. The frontal cortices, as we will discuss, play an important role in mediating cognitive compensation in hearing loss. Given the wide range of variability in behavioral performance following audiological intervention, changes in cortical plasticity may play a valuable role in the prediction of clinical outcomes following intervention. Further, the development of new technologies and rehabilitation strategies that incorporate brain-based biomarkers may help better serve hearing impaired populations across the lifespan.

Evidence and evidence gaps in tinnitus therapy

A nearly endless number of procedures has been tried and in particular sold for the treatment of tinnitus, unfortunately they have not been evaluated appropriately in an evidence-based way. A causal therapy, omitting the tinnitus still does not exist, actually it cannot exist because of the various mechanisms of its origin. However or perhaps because of that, medical interventions appear and reappear like fashion trends that can never be proven by stable and reliable treatment success. This contribution will discuss and acknowledge all current therapeutic procedures and the existing or non-existing evidence will be assessed. Beside external evidence, the term of evidence also encompasses the internal evidence, i.e. the experience of the treating physician and the patient's needs shall be included. While there is no evidence for nearly all direct procedures that intend modulating or stimulating either the cochlea or specific cervical regions such as the auditory cortex, there are therapeutic procedures that are acknowledged in clinical practice and have achieved at least a certain degree of evidence and generate measurable effect sizes. Those are in particular habituation therapy and psychotherapeutic measures, especially if they are combined with concrete measures for improved audio perception (hearing aids, CI, hearing therapies).

Consequences of Stimulus Type on Higher-Order Processing in Single-Sided Deaf Cochlear Implant Users

Single-sided deaf subjects with a cochlear implant (CI) provide the unique opportunity to compare central auditory processing of the electrical input (CI ear) and the acoustic input (normal-hearing, NH, ear) within the same individual. In these individuals, sensory processing differs between their two ears, while cognitive abilities are the same irrespectively of the sensory input. To better understand perceptual-cognitive factors modulating speech intelligibility with a CI, this electroencephalography study examined the central-auditory processing of words, the cognitive abilities, and the speech intelligibility in 10 postlingually single-sided deaf CI users. We found lower hit rates and prolonged response times for word classification during an oddball task for the CI ear when compared with the NH ear. Also, event-related potentials reflecting sensory (N1) and higher-order processing (N2/N4) were prolonged for word classification (targets versus nontargets) with the CI ear compared with the NH ear. Our results suggest that speech processing via the CI ear and the NH ear differs both at sensory (N1) and cognitive (N2/N4) processing stages, thereby affecting the behavioral performance for speech discrimination. These results provide objective evidence for cognition to be a key factor for speech perception under adverse listening conditions, such as the degraded speech signal provided from the CI.

Ipsilateral single stage conversion from BAHA to cochlear implant

Profound unilateral sensorineural hearing loss is an indication for the placement of a bone anchored hearing aid. In a few unfortunate patients who later develop contralateral hearing loss, a cochlear implant becomes a good option. We present our experience in these cases and discuss our technique for single stage conversion from a bone anchored hearing aid to a cochlear implant.

Cochlear implantation for patients with single-sided deafness or asymmetrical hearing loss: a systematic review of the evidence

OBJECTIVE

A systematic review of the literature to evaluate the clinical outcome of cochlear implantation for patients with single-sided deafness (SSD) or asymmetrical hearing loss (AHL).

DATA SOURCES

We searched the PubMed, Embase, Cochrane Library, and CINAHL databases from their inception up to December 10, 2013 for SSD or AHL and cochlear implantation or their synonyms.

STUDY SELECTION

In total, 781 articles were retrieved, of which 15 satisfied the eligibility criteria. Our outcomes of interest were speech perception in noise, sound localization, quality of life (QoL), and tinnitus.

DATA EXTRACTION

Critical appraisal showed that six studies reported on less than five patients or that they carried a low directness of evidence or a high risk of bias. Therefore, we extracted the data of nine studies (n = 112). Patient numbers, age, duration of deafness, classification of deafness, pure tone audiometry, follow-up duration, and outcome measurements were extracted from all nine articles.

DATA SYNTHESIS

Because of large heterogeneity between studies, we were not able to pool data in a meta-analysis. We therefore summarized the results of the studies specified per outcome.

CONCLUSION

There are no high-level-of-evidence studies concerning cochlear implantation in patients with SSD or AHL. Current literature suggests important benefits of cochlear implantation regarding sound localization, QoL, and tinnitus. Varying results were reported for speech perception in noise, possibly caused by the large clinical heterogeneity between studies. Larger and high-quality studies are certainly warranted.

Quantification of speech-in-noise and sound localisation abilities in children with unilateral hearing loss and comparison to normal hearing peers

The study objective was to quantify abilities of children with unilateral hearing loss (UHL) on measures that address known deficits for this population, i.e. speech understanding in quiet and noise, and sound localisation. Noise conditions varied by noise type and source location. Parent reports of real-world abilities were also obtained. Performance was compared to gender- and age-matched normal hearing (NH) peers. UHL performance was poorer and more varied compared to NH peers. Among the findings, age correlated with localisation ability for UHL but not NH participants. Low-frequency hearing in the better ear of UHL children was associated with performance in noise; however, there was no relation for NH children. Considerable variability was evident in the outcomes of children with UHL and needs to be understood as future treatment options are considered.

Improving Health-Related Quality of Life in Single-Sided Deafness: A Systematic Review and Meta-Analysis

Unilateral severe-to-profound hearing loss, or single-sided deafness (SSD), impairs listening abilities supported by the use of two ears, including speech perception in background noise and sound localisation. Hearing-assistive devices can aid listening by re-routing sounds from the impaired to the non-impaired ear or by restoring input to the impaired ear. A systematic review of the literature examined the impact of hearing-assistive devices on the health-related quality of life (HRQoL) of adults with SSD as measured using generic and disease-specific instruments. A majority of studies used observational designs, and the quality of the evidence was low to moderate. Only two studies used generic instruments. A mixed-effect meta-analysis of disease-specific measures suggested that hearing-assistive devices have a small-to-medium impact on HRQoL. The Speech, Spatial and Qualities of Hearing Scale and the Health Utilities Index Mark 3 (HUI3) were identified as instruments that are sensitive to device-related changes in disease-specific and generic HRQoL, respectively.

Cochlear implantation and single-sided deafness

PURPOSE OF REVIEW

Recently, more patients with single-sided deafness (SSD) have been undergoing cochlear implantation. We review recent studies and case reports to provide an overview of the efficacy of cochlear implants to rehabilitate patients with SSD with regards to sound localization, speech discrimination, and tinnitus suppression.

RECENT FINDINGS

There are a growing number of studies evaluating the effect of cochlear implantation for rehabilitation of the deficits associated with SSD over the past several years as more centers offer this treatment modality to patients with SSD. Although individual studies have few patients and are underpowered, the vast majority report improvement in sound localization, speech understanding in quiet and noise, and tinnitus. In some cases, the outcomes with cochlear implant appear superior to those achieved with other devices, including contralateral routing of sound devices and osseointegrated implants.

SUMMARY

Although cochlear implant is not a Food and Drug Administration-approved treatment for SSD, several recent studies show improvements in speech understanding, sound localization, and tinnitus. Because of the low number of cases, it is difficult to conclusively compare outcomes achieved with cochlear implants and those provided by other devices. However, on the basis of encouraging early results and the unique ability to restore binaural sound processing, a growing number of centers offer cochlear implants as treatment for SSD. Forthcoming studies will help define outcome expectations in different populations.

Factors influencing electrical place pitch perception in bimodal listeners

Factors that might affect perceptual pitch match between acoustic and electric stimulation were examined in 25 bimodal listeners using magnitude estimation. Pre-operative acoustic thresholds in both ears, and duration of severe-profound loss, were first examined as correlates with degree of match between the measured pitch and that predicted by the spiral ganglion frequency-position model. The degree of match was examined with respect to (1) the ratio between the measured and predicted pitch percept on the most apical electrode and (2) the ratio between the slope of the measured and predicted pitch function. Second, effect of listening experience was examined to assess whether adaptation occurred over time to match the frequency assignment to electrodes. Pre-experience pitch estimates on the apical electrode were within the predicted range in only 28% of subjects, and the slope of the electrical pitch function was lower than predicted in all except one subject. Subjects with poorer hearing tended to have a lower pitch and a shallower electrical pitch function than predicted by the model. Pre-operative hearing thresholds in the contralateral ear and hearing loss duration were not correlated with the degree of pitch match, and there was no significant group effect of listening experience.