Unexplained Variation in Benefit of Treatment of Congenital Unilateral Aural Atresia: A Review of the Literature.

OBJECTIVE: A review of published data regarding binaural hearing after treatment of congenital unilateral conductive hearing loss (UCHL) due to aural atresia. Treatment options concern atresia surgery (reconstructive surgery), application of a bone conduction device (BCD), or application of a middle ear implant (MEI). DATA SOURCES: Database PubMed was searched for articles published in English and German between January 1, 1994, and January 1, 2019. STUDY SELECTION: The initial search identified 52 studies, of which 9 met the inclusion criteria. DATA SYNTHESIS: Comparison of studies was based on a structured review. Meta-analysis was not feasible because of the heterogeneity of outcome measures, the limited number of relevant papers (9), and diverse types of treatment (5). CONCLUSIONS: Treatment of UCHL results in bilateral hearing instead of binaural hearing. The large intersubject variability in benefit of treatment is unexplained with a clear improvement in the minority of listeners and a limited improvement or binaural interference in most listeners after atresia repair or amplification with a BCD or MEI.

Long-term subjective benefit with a bone conduction implant sound processor in 44 patients with single-sided deafness.

INTRODUCTION: Studies that investigate the subjective benefit from a bone conduction implant (BCI) sound processor in patients with single-sided sensorineural deafness (SSD) have been limited to examining short- and mid-term benefit. In the current study, we performed a survey among 44 SSD BCI users with a median follow-up time of 50 months. MATERIALS AND METHODS: Forty-four experienced SSD BCI users participated in the survey, which consisted of the Abbreviated Profile of Hearing Aid Benefit, the Single-Sided Deafness Questionnaire, the Short Hearing Handicap Inventory for Adults, and a self-made user questionnaire. For patients with tinnitus, the Tinnitus Questionnaire was also completed. The results of the survey were correlated with contralateral hearing loss, age at implantation, duration of the hearing loss at the time of implantation, duration of BCI use, and the presence and burden of tinnitus. RESULTS: In total, 86% of the patients still used their sound processor. The Abbreviated Profile of Hearing Aid Benefit and the Short Hearing Handicap Inventory for Adults show a statistically significant overall improvement with the BCI. The Single-Sided Deafness Questionnaire and the user questionnaire showed that almost 40% of the patients reported daily use of the sound processor. However, the survey of daily use reveals benefit only in certain circumstances. Speech understanding in noisy situations is rated rather low, and 58% of all patients reported that their BCI benefit was less than expected. CONCLUSION: The majority of the patients reported an overall improvement from using their BCI. However, the number of users decreases during a longer follow-up time and patients get less enthusiastic about the device after an extended period of use, especially in noisy situations. However, diminished satisfaction because of time-related reductions in processor function could not be ruled out.

An experimental objective method to determine maximum output and dynamic range of an active bone conduction implant: the Bonebridge.

INTRODUCTION: Recently, a new active bone conduction implant, the Bonebridge, was introduced. This transcutaneous device is proposed as an alternative to previous percutaneous systems. The current study aims to determine the maximum output (MO) of the Bonebridge by making use of Bonebridge-generated sound pressure levels in the occluded ear canal of the unaided ear. METHODOLOGY: The test setup consisted of audiometry and input-output measurements. These tests were performed on 3 Bonebridge users with conductive or mixed hearing loss (bone-conduction thresholds, ≤ 45 dB HL) at least 3 months after implantation surgery. All the patients were implanted and were evaluated in the Antwerp University Hospital. The MO of the device was determined by measuring input-output functions with a microphone placed in the occluded contralateral ear canal using the Aurical REM system. During testing, the sound processor was fitted in linear amplification mode and with unlimited output to determine the MO and the input dynamic range of the Bonebridge. This experimental setup intends to evaluate the device in a fitting program without compression. RESULTS: The mean MO of the device was 55 dB HL (SD, 6 dB HL) at 0.5 kHz, 61 dB HL (SD, 18 dB HL), 71 dB HL (SD, 10 dB HL) at 2 kHz, and 60 dB HL (SD, 10 dB HL) at 4 kHz. The mean dynamic range of the Bonebridge was 41 (SD, 5) dB HL, 46 (SD, 10) dB HL, 46 (SD, 5) dB HL, and 37 (SD, 16) dB HL for 0.5, 1, 2, and 4 kHz, respectively. CONCLUSION: In summary, ear canal measures can effectively be used to assess input-output behavior of the Bonebridge. The present study indicates that the MO of the Bonebridge ranges from 55 to 71 dB HL, depending on frequency. Accepting a minimum dynamic range of 35 dB with the Bonebridge, fitting of the Bonebridge in a linear program is advocated in patients with a sensorineural hearing loss component of up to 30 dB HL.

A comparative study on speech in noise understanding with a direct acoustic cochlear implant in subjects with severe to profound mixed hearing loss.

The aim of this study was to investigate the efficacy of a direct acoustic cochlear implant (DACI) for speech understanding in noise in patients suffering from severe to profound mixed hearing loss (MHL) due to various etiologies compared to the preoperative best-aided condition. The study was performed at five tertiary referral centers in Europe (Belgium, Germany, Poland and Spain). Nineteen adult subjects with severe to profound MHL due to (advanced) otosclerosis, ear canal fibrosis, chronic otitis media, tympanosclerosis or previous cholesteatoma were implanted with a DACI (Codacs™ Investigational Device) combined with a conventional stapes prosthesis. Unaided and aided speech reception scores in quiet and in noise, preoperative and postoperative air and bone conduction thresholds and aided and unaided sound field thresholds were measured prospectively during the study. Subjective benefit analysis was determined through the Abbreviated Profile of Hearing Aid Benefit questionnaire. Quality of life was measured by the Health Utilities Index. All subjects were fitted preoperatively with hearing aids and/or a bone conduction implant on a headband before DACI implantation. This allows direct comparison between different hearing rehabilitation solutions. The mean speech reception threshold in noise improved significantly by 7.9 dB signal-to-noise ratio (SNR) after activation of the DACI compared to the preoperative best-aided condition. For all 19 subjects, a mean postoperative aided speech reception threshold of 2.6 dB SNR (standard deviation: 8.3 dB) was measured. On average, no significant shift in the bone conduction thresholds was noted 4-5 months after implantation. A mean sound field threshold improvement of 46 and 16 dB was measured compared to the preoperative unaided and best-aided condition, respectively. Speech perception tests in quiet showed a mean improvement of the word recognition scores by 65 and 48% at 65 dB SPL compared to the preoperative unaided and best-aided condition, respectively. In summary, DACI provides an effective improvement of the speech perception in noise compared to the best-aided condition in subjects suffering from severe to profound MHL.

Comparison of sound processing strategies for osseointegrated bone conduction implants in mixed hearing loss: multiple-channel nonlinear versus single-channel linear processing.

OBJECTIVES: Evaluation of a single-channel linear bone conduction implant sound processor (S-BCI) and a multiple-channel nonlinear bone conduction implant sound processor (M-BCI) with objective and subjective measures in patients with mixed hearing loss. STUDY DESIGN: In total, 20 patients with mixed hearing loss were included in the study. For either sound processor aided thresholds and speech perception in quiet with monosyllables were measured. Speech perception in noise was measured with sentences. Two different configurations were used: speech and noise at 0° (S0N0) and speech at 0° and noise at 180° (S0N180). The M-BCI was tested in both omnidirectional and directional mode. Patients were first fitted with the S-BCI and evaluated 3 weeks later. The M-BCI was fitted and, again 3 weeks later, evaluated. Subjectively, patients compared both sound processors with the APHAB questionnaire. RESULTS: Aided thresholds were similar for both sound processors in the low- and mid-frequency range. For speech in quiet, no significant differences between both sound processors were observed. For speech in noise in the S0N0 condition, the M-BCI-thresholds were 1.7 dB (SD, 2.2dB; p = 0.002) more favorable than with S-BCI. For the S0N180 configuration, an improvement of 5.8 dB (SD, 2.8 dB; p < 0.001) was seen for the directional mode relative to S-BCI. The APHAB showed statistically significant subjective improvement with the M-BCI on all subscales relative to S-BCI. CONCLUSION: Speech intelligibility in noise is better with M-BCI than with S-BCI. This was attributed to better high-frequency gain provided by the M-BCI. Improved signal processing strategies may have contributed to subjective preference for the M-BCI.

Comparison of 2 implantable bone conduction devices in patients with single-sided deafness using a daily alternating method.

OBJECTIVE: Comparison of the auditory and subjective capabilities of 2 implantable bone conduction devices BAHA Divino sound processor (Divino) and the BAHA BP100 sound processor (BP100) using a daily alternating method. STUDY DESIGN: Open prospective comparative trial. SETTING: Tertiary referral otology and neurotology center. PATIENTS: Ten patients with single-sided deafness (SSD) using a Divino for more than 1 year. INTERVENTIONS: The patients with SSD changed to the BP100 for 1 week, and then underwent an evaluation period of 18 days switching between BP100 and Divino on a daily alternating basis. On a scale from 0 to 10, patients rated their quality of hearing daily with both devices concerning overall satisfaction, clearness of sound, and effort of listening in background noise. For the total duration of the trial, the spatial hearing questionnaire (SHQ) and the abbreviated profile of hearing aid benefit (APHAB) were administered. In the unaided condition and with Divino at baseline and aided with BP100 after the evaluation period, adaptive speech in quiet and in noise testing was performed with speech and noise coming from different azimuth angles. MAIN OUTCOME MEASURES: Subjective rating in a diary, APHAB, SHQ, and aided speech in quiet and speech in noise. RESULTS: The diary shows significant improvement on all subscales with BP100 in comparison with Divino. These differences did not change significantly during 18 days. On the APHAB, listening in background noise and in reverberant conditions was rated significantly better with the BP100. The SHQ shows a significant difference between both devices on all subscales except for source localization and speech understanding in quiet. Speech audiometry showed a significant head shadow benefit with both implantable bone conduction devices (median [Q1, Q3]: Divino = 2.67 dB [0.33, 1.51], BP100 = 2.83 dB [4.08, 3.83]). There was no significant difference found between both devices. CONCLUSION: Both the Divino and the BP100 reduce the handicap experienced by patients with SSD. Subjective assessment using a daily alternating method shows higher overall hearing capabilities with BP100. Results of the questionnaires are similar. Speech audiometry in noise does not reveal a statistically significant difference between both devices. A daily alternating method can provide useful information for both the patient and the audiologist because objective measurements do not show any statistically significant differences between patients. In our opinion, daily alternation of devices is a useful method to compare different devices.

Clinical need for a Baha trial in patients with single-sided sensorineural deafness. Analysis of a Baha database of 196 patients.

A bone-anchored hearing aid (Baha) is used in patients with single-sided sensorineural deafness (SSD) to overcome the head shadow effect. Of all the patients with SSD, treated at our hospital, 196 patients used a Baha on trial between November 2001 and April 2010. The objective of this study is to evaluate what factors determine the decision of a SSD patient whether or not to opt for a Baha device following a Baha trial period. 196 patients with SSD were enrolled for a trial period of 2 weeks at the Antwerp University Hospital, a tertiary referral centre. 93% of these patients suffered from an acquired hearing loss. 44% of all the patients (87/196) chose to wear a Baha device after the trail period, either on an abutment or on a headband. The collected data were analysed to determine correlations between the decision of a patient following a Baha trial period on the one hand, and Fletcher Index ipsi- and contralaterally, bone conduction hearing thresholds at the better hearing ear, aetiology, age at the start of the trial period, duration of hearing loss at the start of the trial period and the type of device used during the trial period, on the other hand. Although 66% of all the patients (109/196) declined the Baha after a trial, reasons not to choose a Baha were diverse and no crucial factors could be found that determine the success of a Baha trial period. Lack of improvement concerning speech understanding in noise was the most important reason mentioned by patients who declined the Baha. The authors advocate that all patients, suffering from SSD, should be offered the opportunity to try a Baha device as no factors could be found that determine the decision of a patient following the trial period.