Myrthe K. S. Hol

Bone-anchored hearing aid in unilateral inner ear deafness: a study of 20 patients.

Objective: To evaluate the benefit of a bone-anchored hearing aid (BAHA) contralateral routing of sound (CROS) in 20 patients with unilateral inner ear deafness. Subjects: 21 patients were recruited; 15 had undergone acoustic neuroma surgery and 6 patients had unilateral profound hearing loss due to other causes; 1 patient was excluded. Only patients with thresholds of better than 25 dB HL (500–2000 Hz) and an air-bone gap of less than 10 dB in the best ear were included. Methods: Evaluation involved audiometric measurements before intervention, when fitted with a conventional CROS and after implementation and quantification of the patients’ subjective benefit with a hearing aid-specific instrument: the Abbreviated Profile of Hearing Aid Benefit (APHAB). Results: Lateralization scores were not significantly different from chance (50%) in any of the three conditions. Measurements of speech perception in noise showed an increase in the signal to noise ratio (S/N ratio) with the conventional CROS (p = 0.001) and with the BAHA CROS compared to the unaided condition when speech was presented at the front with noise on the poor hearing side. On the other hand, a lower S/N ratio was seen with the BAHA CROS (p = 0.003) compared to the unaided situation when noise was presented at the front with speech on the poor hearing side. The patient outcome measure (APHAB) showed improvement, particularly with the BAHA CROS. Conclusions: The poor sound localization results illustrate the inability of patients with unilateral inner ear deafness to localize sounds. The speech-in-noise measurements reflect the benefit of a BAHA CROS in lifting the head shadow while avoiding some of the disadvantages of a conventional CROS. The benefit of the BAHA CROS was most clearly reflected in the patients’ opinion measured with the APHAB.

The Baha Softband A new treatment for young children with bilateral congenital aural atresia

The Baha (bone-anchored hearing aid) Softband appears to be an effective mean of hearing rehabilitation for children with a congenital bilateral aural atresia who are too young for the amplification of a Baha on an implant. The aided hearing threshold with a Baha Softband is almost equal to that achieved with a conventional bone conductor. The speech development of the children studied with a Baha Softband is on a par with peers with good hearing.

Bone-anchored hearing aid system application for unilateral congenital conductive hearing impairment: audiometric results.

Objective: To study the audiologic outcome of bone-anchored hearing aid (BAHA) application in patients with congenital unilateral conductive hearing impairment. Study Design: Prospective audiometric evaluation on 20 patients. Setting: Tertiary referral center. Patients: The experimental group comprised 20 consecutive patients with congenital unilateral conductive hearing impairment, with a mean air-bone gap of 50 dB. Methods: Aided and unaided hearing was assessed using sound localization and speech recognition-in-noise tests. Results: Aided hearing thresholds and aided speech perception thresholds were measured to verify the effect of the BAHA system on the hearing acuity. All patients fulfilled the criteria that the aided speech reception thresholds or the mean aided sound field thresholds were 25 dB or better in the aided situation. Most patients were still using the BAHA almost every day. Sound localization scores varied widely in the unaided and aided situations. Many patients showed unexpectedly good unaided performance. However, nonsignificant improvements of 3.0 (500 Hz) and 6.9 degrees (3,000 Hz) were observed in favor of the BAHA. Speech recognition in noise with spatially separated speech and noise sources also improved after BAHA implantation, but not significantly. Conclusion: Some patients with congenital unilateral conductive hearing impairment had such good directional hearing and speech-in-noise scores in the unaided situation that no overall significant improvement occurred after BAHA fitting in our setup. Of the 18 patients with a complete data set, 6 did not show any significant improvement at all. However, compliance with BAHA use in this patient group was remarkably high. Observations of consistent use of the device are highly suggestive of patient benefit. Further research is recommended to get more insight into these findings.

Comparison between a new implantable transcutaneous bone conductor and percutaneous bone-conduction hearing implant

Objectives Despite good results on osseointegration and limited skin reactions with percutaneous bone conductors, there remains room for improvement. Especially in children, adverse events with percutaneous bone conductors might occur more frequently. Transcutaneous bone conductors, if powerful enough, can provide a solution that minimizes adverse events and implant loss. This study compares a new transcutaneous bone conduction hearing aid, the Sophono Alpha 1 (Sophono), with the percutaneous BAHA system (BAHA). Methods In our tertiary referral center, 12 patients (age 5–12 yr) with congenital unilateral conductive hearing loss were enrolled in the study as follows: 6 patients with the Sophono and 6 with the BAHA. Both clinical results and audiologic data were gathered. For an objective audiologic comparison between both systems, we used a skull simulator. Results The skin reactions were comparable between both groups, in 1 implant was lost 1 month after second phase surgery (BAHA). The users received audiologic benefits from both systems. The BAHA-based outcome was slightly better compared with Sophono-based results in sound field thresholds, speech recognition threshold, and speech comprehension at 65 dB. The skull simulator demonstrated that the BAHA device has an output that is 10 to 15 dB higher compared with the Sophono device. Conclusion The Sophono offers appealing clinical benefits of transcutaneous bone conduction hearing; however, the audiologic challenges of transcutaneous application remain, as the Sophono does not exceed percutaneous application regarding audiologic output.

Bone-Anchored Hearing Aids in Patients with Acquired and Congenital Unilateral Inner Ear Deafness (Baha CROS): Clinical Evaluation of 56 Cases:

Objectives We performed an evaluation of the audiological and subjective benefits of the bone-anchored hearing aid (Baha) as a device for transcranial routing of sound (Baha CROS) in 56 patients with unilateral inner ear deafness. Methods We performed a prospective clinical follow-up study in a tertiary referral center. Previously reported results of 29 patients were supplemented with a second series of 30 patients with unilateral inner ear deafness; 3 patients dropped out during the evaluation. Audiometric measurements were taken before and after Baha CROS fitting. Subjective benefits were quantified with 4 different patient questionnaires. Results The sound localization results in a well-structured test setting were not differentiable from chance. The 5 patients with congenital hearing loss showed better scores in the unaided sound localization measurements. Overall, most patients reported some subjective improvement in their capacity to localize sounds with the Baha CROS in daily life. The main effect of the Baha CROS was to alleviate the head shadow effect during the speech-in-noise test. Conclusions Poor sound localization in this larger series of patients confirms the findings of previous studies. Improvements in the speech-in-noise scores corroborated the efficacy of the Baha CROS in alleviating the head shadow effect. The 4 different patient questionnaires revealed subjective benefit and satisfaction in various domains.

Bone-anchored hearing implant loading at 3 weeks: stability and tolerability after 6 months.

Objective To clinically evaluate the performance of a titanium percutaneous bone-anchored hearing implant (BAHI) using a 3-week healing period. Short-term implant survival, stability changes, and skin reactions are evaluated from the initial implantation to 6 months postimplantation. Methods Thirty patients eligible for a BAHI were included in an open, prospective clinical investigation. Implant stability quotient (ISQ) values were recorded using resonance frequency analysis (RFA) at the time of implantation and at 10 days; at 3, 6, and 12 weeks; and at 6 months after placement of the implant. Sound processor fitting was performed 3 weeks after implantation. Skin reactions were evaluated according to the Holgers classification. Results One implant was lost 3 days after implantation because of poor bone quality. No implant loss occurred in the remaining 29 patients (96.7%). The mean ISQ value at the time of implantation was 67.1 (range, 44–71). Compared with baseline, there was a significant dip of -2.2 ISQ units at 10 days (mean, 65.7; p = 0.0093). There was a positive change in mean ISQ compared with baseline over the subsequent visits. No reduction in mean ISQ values was observed after implant loading. Skin reactions were observed incidentally (mean over all visits, 9.7%) and were generally mild (Holgers Grade 1; mean 9.0%). An adverse skin reaction (Holgers Grade 2) was observed only once (mean, 0.7%). Conclusion The current study suggests that loading the implant and 6-mm abutment with the sound processor at 3 weeks is safe. The stability of the implant as measured by ISQ values had reached its baseline value within 3 weeks after implantation. The degree of stability was not affected by implant loading. Only mild skin reactions were observed incidentally. This study supports the use of early loading at 3 weeks as current practice in healthy adults with good bone quality; thus, these adults can benefit from the rehabilitation of their hearing at an earlier stage.

Does the Bone-Anchored Hearing Aid Have a Complementary Effect on Audiological and Subjective Outcomes in Patients with Unilateral Conductive Hearing Loss?

Objectives: To study the effect of a bone-anchored hearing aid (BAHA) in patients with unilateral conductive hearing loss. Study Design: Prospective evaluation on 18 subjects. Methods:Aided and unaided binaural hearing was assessed in the sound field using a sound localization test and a speech recognition in noise test with spatially separated sound and noise sources. The patients also filled out a disability-specific questionnaire. Patients: 13 out of the 18 subjects had normal hearing on one side and acquired conductive hearing loss in the other ear. The remaining 5 patients had a unilateral air-bone gap and mild symmetrical sensorineural hearing loss. Results:Sound localization with the BAHA improved significantly. Speech recognition in noise with spatially separated speech and noise sources also improved with the BAHA. Fitting a BAHA to patients with unilateral conductive hearing loss had a complementary effect on hearing. Questionnaire results showed that the BAHA was of obvious benefit in daily life. Conclusions: The BAHA proved to be a beneficial means to optimize binaural hearing in patients with severe (40–60 dB) unilateral conductive hearing loss according to audiometric data and patient outcome measures.

Benefit and quality of life after bone-anchored hearing aid fitting in children with unilateral or bilateral hearing impairment

OBJECTIVE To evaluate the benefits of a bone-anchored hearing aid (BAHA) in the daily lives of hearing-impaired children. DESIGN Retrospective questionnaire study. SETTING Nijmegen Medical Centre, Nijmegen, the Netherlands. PATIENTS Thirty-eight BAHA users with a minimum age of 4 years at BAHA fitting and 1 to 4 years of use, divided into groups with bilateral conductive or mixed hearing loss and either normal cognition or mental disability and a group with unilateral conductive hearing loss. MAIN OUTCOME MEASURES Scores on the Glasgow Childrens Benefit Inventory, Abbreviated Profile of Hearing Aid Benefit, and Health Utilities Index Mark 3. RESULTS The Glasgow Childrens Benefit Inventory showed a subjective overall benefit of +32, +16, and +26 in the 3 groups (on a scale of -100 to +100). The Abbreviated Profile of Hearing Aid Benefit also showed an overall mean benefit in the groups. On an individual level, a clinically significant benefit was reported by more children in the group with bilateral hearing loss and normal cognition (7 patients [70%]) than in the unilateral hearing loss group (4 patients [27%]). Overall mean health utility scores and disability index scores on the Health Utility Index Mark 3 were comparable among the 3 groups. CONCLUSION Overall, BAHA fitting can be considered effective and beneficial in children with bilateral or unilateral hearing loss.

Improved horizontal directional hearing in bone conduction device users with acquired unilateral conductive hearing loss

We examined horizontal directional hearing in patients with acquired severe unilateral conductive hearing loss (UCHL). All patients (n = 12) had been fitted with a bone conduction device (BCD) to restore bilateral hearing. The patients were tested in the unaided (monaural) and aided (binaural) hearing condition. Five listeners without hearing loss were tested as a control group while listening with a monaural plug and earmuff, or with both ears (binaural). We randomly varied stimulus presentation levels to assess whether listeners relied on the acoustic head-shadow effect (HSE) for horizontal (azimuth) localization. Moreover, to prevent sound localization on the basis of monaural spectral shape cues from head and pinna, subjects were exposed to narrow band (1/3 octave) noises. We demonstrate that the BCD significantly improved sound localization in 8/12 of the UCHL patients. Interestingly, under monaural hearing (BCD off), we observed fairly good unaided azimuth localization performance in 4/12 of the patients. Our multiple regression analysis shows that all patients relied on the ambiguous HSE for localization. In contrast, acutely plugged control listeners did not employ the HSE. Our data confirm and further extend results of recent studies on the use of sound localization cues in chronic and acute monaural listening.

Contribution of monaural and binaural cues to sound localization in listeners with acquired unilateral conductive hearing loss: improved directional hearing with a bone-conduction device.

Sound localization in the horizontal (azimuth) plane relies mainly on interaural time differences (ITDs) and interaural level differences (ILDs). Both are distorted in listeners with acquired unilateral conductive hearing loss (UCHL), reducing their ability to localize sound. Several studies demonstrated that UCHL listeners had some ability to localize sound in azimuth. To test whether listeners with acquired UCHL use strongly perturbed binaural difference cues, we measured localization while they listened with a sound-attenuating earmuff over their impaired ear. We also tested the potential use of monaural pinna-induced spectral-shape cues for localization in azimuth and elevation, by filling the cavities of the pinna of their better-hearing ear with a mould. These conditions were tested while a bone-conduction device (BCD), fitted to all UCHL listeners in order to provide hearing from the impaired side, was turned off. We varied stimulus presentation levels to investigate whether UCHL listeners were using sound level as an azimuth cue. Furthermore, we examined whether horizontal sound-localization abilities improved when listeners used their BCD. Ten control listeners without hearing loss demonstrated a significant decrease in their localization abilities when they listened with a monaural plug and muff. In 4/13 UCHL listeners we observed good horizontal localization of 65 dB SPL broadband noises with their BCD turned off. Localization was strongly impaired when the impaired ear was covered with the muff. The mould in the good ear of listeners with UCHL deteriorated the localization of broadband sounds presented at 45 dB SPL. This demonstrates that they used pinna cues to localize sounds presented at low levels. Our data demonstrate that UCHL listeners have learned to adapt their localization strategies under a wide variety of hearing conditions and that sound-localization abilities improved with their BCD turned on.