Bone-anchored Hearing Aid Users Research Articles

Comparative analysis between effective gain and functional gain in bone-anchored hearing aid users.

The cases of ear malformations, conductive, mixed, and single-sided deafness hearing loss are candidates for surgery and use of Bone-Anchored Hearing Aids (BAHA). Commonly, the literature highlights two procedures to assess the benefits and characteristics of amplification in users: functional gain (FG) and effective gain (EG). Estimate and compare the EG and the FG to evaluate the benefits obtained by users of BAHA and, later, to compare tests of speech perception in silence and in noise. The sample (n=79) was divided into four groups, implanted from February 2014 to February 2021. The following tests were analyzed: pure-tone audiometry by air and bone; research of audiometric thresholds in free field; speech perception tests in silence and in noise. EG presented lower values than FG in all frequencies. The positive results of the speech perception tests were correlated with worse FG values. EG is the best method for evaluation, as it allows a proper comparison between devices, as well as a comparison with the prescription of validated rules. A better evaluation of results was observed on the EG values, indicating that it is a relevant method to assess auditory performance. In addition, the FG results were incompatible with the benefits obtained in the speech perception tests, showing that it is not a reliable tool for monitoring the results with the use of BAHA.

Online support group users’ perceptions and experiences of bone-anchored hearing aids (BAHAs): a qualitative study

Objective: Better understanding of the decision-making process for bone-anchored hearing aid (BAHA) candidates has been identified by clinicians as a research priority. This study aimed to understand experiences and perceptions of BAHA candidates and users who use online support groups.Design: One thousand posts retrieved from a public UK-based online support group were thematically analysed.Study sample: Messages were posted by 270 BAHA users and candidates.Results: Individuals used the online group to obtain information about BAHAs and support for decision-making regarding accepting BAHA surgery and wearing a percutaneous device. BAHA users evaluated the efficacy of the system, perceiving it to be highly effective in improving their hearing. The BAHA influenced individuals’ self-image and impacted their social lives. Fears of surgery and post-implantation infections were regarded as challenges to be faced when choosing to accept implantation.Conclusions: BAHA candidates found the online support group useful in helping them to decide whether or not to proceed with surgery, and the personal experiences of BAHA users were predominantly positive. However, it is not clear to what extent such positive experiences are representative of BAHA users more generally, and candidates need to be aware of this when using these groups to support decision-making.

Application of Acceptable Noise Level to Confirm Fitting Strategy for Bone-Anchored Hearing Aid

Since there is no standardized fitting procedure for bone-anchored hearing aid (BAHA) patients, many clinics have failed to perform their successful fitting. The present case study tried to identify whether acceptable noise level (ANL) was clinically applied as one of fitting procedures for the BAHA users. Four hearing-impaired adults with BAHA (3 female and 1 male) who had a period of hearing deprivation for at least 8 years and the BAHA experience of more than 1 year participated. They conducted ANL in their unaided and aided BAHA conditions after being familiar with the ANL instruction. Also, the subjects responded to a self-report of Korean version of Profile of Hearing Aid Benefit (K-PHAB) to subjectively check amount of satisfaction with BAHA. Compared to the unaided condition, two out of four BAHA users showed a decreased ANL in the aided condition whereas the other users had a slightly increased ANL. Regardless, their levels were examined within the permissible range except for one subject. Their K-PHAB scores were similar to the ANL results in the aided condition. Although measured ANLs were slightly differed from the users, the current results suggest that ANL might be a tool to measure individual’s inherent value when the BAHA fitting being appropriated while also supported by K-PHAB scores. In the following study, we need to confirm a typical pattern of many BAHA users with longitudinal measures of ANL.

Evaluation of auditory temporal processing in patients fitted with bone-anchored hearing aids.

The present study aimed to identify temporal processing abilities in users of bone-anchored hearing aid (BAHA). Seventeen subjects with BAHA (SWB) users and 29 subjects with normal-hearing were compared using the frequency pattern test, duration pattern test, and speech-in-noise test. Besides behavioral temporal processing tests, a multi-feature mismatch negativity (MMN) test was performed in BAHA users to assess the accuracy of objective auditory discrimination at the cortical level, irrespective of the subjects' attention or behavioral task. The results of the multi-feature MMN test showed that BAHA users could perceive differences in frequency, duration, intensity. However, no response was elicited regarding localization of stimulus and gaps within tones. Word recognition performance in noise was significantly poorer compared with normal hearing groups. All age groups showed no differences in terms of temporal processing abilities except 30-39years duration pattern ability weaker in SWB group. The present study was the first to indicate that the use of unilateral BAHA has no effect on the localization of auditory stimuli at the cortical level according to electrophysiological test. Although Baha users have near-normal levels of hearing thresholds and temporal ordering abilities with their devices, since they benefit from the unilateral device, they still have some difficulties in resolution, recognizing and distinguishing the spatial aspects of speech, especially in multiple and noisy listening environments.

Hearing Rehabilitation through Bone-Conducted Sound Stimulation: Preliminary Results.

Introduction The bone-anchored hearing aid (BAHA) is a bone conduction system that transmits the sound directly to the inner ear by surpassing the skin impedance and the subcutaneous tissue. It is indicated for patients with mixed, conductive and unilateral sensorineural hearing loss who did not benefit from conventional hearing aids (HAs). Although the benefits from BAHA are well demonstrated internationally, this field still lacks studies in Brazil. Objective To assess the auditory rehabilitation process in BAHA users through audiological, speech perception and tinnitus aspects. Methods Individuals with hearing loss were assessed before and after the implantation. The participants were subjected to pure tone audiometry in free field, functional gain audiometry, speech perception tests, tinnitus handicap inventory (THI) in open format, and to the visual analog scale (VAS). Results It was found that the participants benefited from the use of BAHA. The difference in the performance of the participants before and after the BAHA surgery was significant in terms of hearing acuity. There was no statistically significant difference in the speech perception tests. The tinnitus assessment showed that 80% of the participants scored slight tinnitus severity in THI after using a BAHA. Eighty percent of the participants classified their tinnitus as absent to mild in the VAS after the surgery. Conclusion Based on the results of the current study, we can conclude that the participants improved both the auditory perception and the tinnitus handicap.

Surgical and Audiologic Comparison Between Sophono and Bone-Anchored Hearing Aids Implantation.

Objectives Bone-anchored hearing aids (BAHA) occasionally cause soft tissue problems due to abutment. Because Sophono does not have abutment penetrating skin, it is thought that Sophono has no soft tissue problem relating to abutment. On the other hand, transcutaneous device’s output is reported to be 10 to 15 dB lower than percutaneous device. Therefore, in this study, Sophono and BAHA were compared to each other from surgical and audiological points of view.Methods We retrospectively reviewed the medical records of 9 Sophono patients and 10 BAHA patients. In BAHA cases, single vertical incision without skin thinning technique was done. We compared Sophono to BAHA by operation time, wound healing time, postoperative complications, postoperative hearing gain after switch on, and postoperative air-bone gap.Results The mean operation time was 60 minutes for Sophono and 25 minutes for BAHA. The wound healing time was 14 days for Sophono and 28 days for BAHA. No major intraoperative complication was observed. Skin problem was not observed in the 2 devices for the follow-up period. Postoperative hearing gain of bilateral aural atresia patients was 39.4 dB for BAHA (n=4) and 25.5 dB for Sophono (n=5). However, the difference was not statistically significant. In all patients included in this study, the difference of air-bone gap between two groups was 16.6 dB at 0.5 kHz and 18.2 dB at 4 kHz. BAHA was statistically significantly better than Sophono.Conclusion Considering the audiologic outcome, BAHA users were thought to have more audiologic benefit than Sophono users. However, Sophono had advantages over BAHA with abutment in cosmetic outcome. Sophono needed no daily skin maintenance and soft tissue complication due to abutment would not happen in Sophono. Therefore, a full explanation about each device is necessary before deciding implantation.

Using Speech Recall in Hearing Aid Fitting and Outcome Evaluation Under Ecological Test Conditions

In adaptive Speech Reception Threshold (SRT) tests used in the audiological clinic, speech is presented at signal to noise ratios (SNRs) that are lower than those generally encountered in real-life communication situations. At higher, ecologically valid SNRs, however, SRTs are insensitive to changes in hearing aid signal processing that may be of benefit to listeners who are hard of hearing. Previous studies conducted in Swedish using the Sentence-final Word Identification and Recall test (SWIR) have indicated that at such SNRs, the ability to recall spoken words may be a more informative measure. In the present study, a Danish version of SWIR, known as the Sentence-final Word Identification and Recall Test in a New Language (SWIRL) was introduced and evaluated in two experiments. The objective of experiment 1 was to determine if the Swedish results demonstrating benefit from noise reduction signal processing for hearing aid wearers could be replicated in 25 Danish participants with mild to moderate symmetrical sensorineural hearing loss. The objective of experiment 2 was to compare direct-drive and skin-drive transmission in 16 Danish users of bone-anchored hearing aids with conductive hearing loss or mixed sensorineural and conductive hearing loss. In experiment 1, performance on SWIRL improved when hearing aid noise reduction was used, replicating the Swedish results and generalizing them across languages. In experiment 2, performance on SWIRL was better for direct-drive compared with skin-drive transmission conditions. These findings indicate that spoken word recall can be used to identify benefits from hearing aid signal processing at ecologically valid, positive SNRs where SRTs are insensitive.

Digital processing technology for bone-anchored hearing aids: randomised comparison of two devices in hearing aid users with mixed or conductive hearing loss

This study compared the performance of two new bone-anchored hearing aids with older bone-anchored hearing aids that were not fully digital. Fourteen experienced bone-anchored hearing aid users participated in this cross-over study. Performance of their existing bone-anchored hearing aid was assessed using speech-in-noise testing and questionnaires. Participants were then fitted with either a Ponto Pro or a BP100 device. After four weeks of use with each new device, the same assessments were repeated. Speech-in-noise testing for the 50 per cent signal-to-noise ratio (the ratio at which 50 per cent of responses were correct) showed no significant differences between the Ponto Pro and the BP100 devices (p = 0.1) However, both devices showed significant improvement compared with the participants' previous bone-anchored hearing aid devices (p < 0.001). There were no significant differences between the two new devices in the questionnaire data. Both fully digital bone-anchored hearing aids demonstrated superior speech processing compared with the previous generation of devices. There were no substantial differences between the two digital devices in either objective or subjective tests.

Hearing gain with a BAHA test-band in patients with single-sided deafness

PurposeIt is assumed that preoperative use of a bone-anchored hearing aid (BAHA) test-band will give a patient lower gain compared to real post-operative gain because of the reduction of energy through the scalp when using a test-band. Hearing gains using a BAHA test-band were analyzed in patients with unilateral hearing loss. Materials and MethodsNineteen patients with unilateral sensorineural hearing loss were enrolled. A test-band, which was connected to BAHA Intenso with full-on gain, was put on the mastoid. Conventional air-conduction (AC) pure-tone averages (PTAs) and sound-field PTAs and speech reception thresholds (SRTs) were obtained in conditions A (the better ear naked), B (the better ear plugged), and C (the better ear plugged with a test-band on the poorer mastoid). ResultsAir-conduction PTAs of the poorer and better ears were 91±19 and 18±8dB HL. Sound-field PTAs in condition B were higher than those in condition A (54 vs. 26dB HL), which means that earplugs can block the sound grossly up to 54dB HL through the better ears. The aided PTAs (24±6dB HL) in condition C were similar to those of the better ears in condition A (26±9dB HL), though condition C showed higher thresholds at 500Hz and lower thresholds at 1 and 2kHz when compared to condition A. The hearing thresholds using a test-band were similar to the published results of BAHA users with the volume to most comfortable level (MCL). ConclusionOur findings showed that a BAHA test-band on the poorer ear could transmit sound to the cochlea as much as the better ears can hear. The increased functional gain at 1 and 2kHz reflects the technical characteristics of BAHA processor. The reduction of energy through the scalp when using a test-band seems to be offset by the difference of output by setting the volume to full-on gain and using a high-powered speech processor. Preoperative hearing gains using a test-band with full-on gain seems to be similar to the post-operative gains of BAHA users with the volume to MCL.

Efficacy in patients with outer and middle ear deformities of using bone-anchored hearing aids

To evaluate the efficacy and satisfaction of bone-anchored hearing aids (BAHA) in patients with outer and middle ear deformities. Seven patients with bilateral microtia and aural atresia, and three patients with unilateral microtia and bilateral middle ear malformation were fitted with soft-band BAHA for a few months, followed by receiving unilateral BAHA implantation. Mean pure-tone thresholds and speech audiometry tests results were compared among patients without hearing aid, with soft-band BAHA, and with implanted BAHA. Scores from the BAHA users' questionnaires and Glasgow children's benefit inventory (GCBI) were used to measure patient satisfaction and subjective health benefit. The mean pure-tone thresholds of the patients were (64.8 ± 5.9) dBHL for those without hearing aid, (30.2 ± 3.7) dBHL for those with soft-band BAHA, and (20.3 ± 3.9) dBHL for those with implanted BAHA. The average decline in pure-tone threshold was (36.2 ± 8.0) dBHL for those with soft-band BAHA, and an additional decline of (12.2 ± 3.4) dBHL was achieved with implanted BAHA. The average gains in speech discrimination scores (SDS) were (3.00 ± 1.07)% for those without hearing aids and (89.39 ± 5.83)% for those with implanted BAHA in sound field of 45dBHL. SDS were (57.55 ± 10.30)% for those without hearing aids and (91.19 ± 4.16)% for those with implanted BAHA in sound field of 65dBHL. The average gains in SDS were (88.21 ± 6.86)% and (38.04 ± 7.56)% tested with 45dBHL and 65dBHL respectively. Sound reception thresholds (SRT) without hearing aids were (63.1 ± 5.9) dBHL and (24.7 ± 3.5) dBHL for those with implanted BAHA. The average gains in SRT was (39.6 ± 6.2) dBHL. The BAHA application questionnaire demonstrated excellent patient satisfaction. The general benefit score was 35.59 ± 14.35. BAHA remains one of the most reliable methods of auditory rehabilitation and improves quality of life for patients with ear deformities.

Implant survival rate in bone-anchored hearing aid users: long-term results

To investigate the long-term survival rate of bone-anchored hearing aid implants, and to assess the number of patients who stop using their bone-anchored hearing aid. Patients who underwent bone-anchored hearing aid surgery between September 1977 and December 1986 were identified from a prospective database. Data were collected from patient records. During the study period, 143 patients were fitted with a bone-anchored hearing aid. Records from 132 patients were found, with a mean follow up of nine years. A total of 150 implants were installed in these patients. A total of 41 implants (27 per cent) were lost during follow up: 17 lost osseointegration, 16 were removed and eight were lost due to direct trauma. At the end of follow up, 119/132 (90 per cent) patients were still using their bone-anchored hearing aid. Despite a high incidence of implant loss over time, a large number of patients still continued to use their bone-anchored hearing aid.

Quality of life improvement for bone-anchored hearing aid users and their partners

Bone-anchored hearing aid recipients experience well documented improvements in their audiometric performance and quality of life. While hearing aid recipients may understate their functional improvement, their partners may be more aware of such improvement. We sought to investigate patients' partners' perceptions of functional improvement following bone-anchored hearing aid fitting. Surveys were sent to 153 patients who had received a bone-anchored hearing aid through the Nova Scotia bone-anchored hearing aid programme. The validated survey asked patients' partners to give their subjective impression of the bone-anchored hearing aid recipient's functional status. Surveys were completed by 90 patients (58.8 per cent), of whom 72 reported having a partner. Partners reported a significant improvement in hearing (p ≤ 0.0001). Partners reported improvement in 87.0 per cent of functional scenarios, no change in 12.6 per cent, and a decline in 0.4 per cent. These findings demonstrate a significant improvement in the emotional and social effects of hearing impairment, as perceived by bone-anchored hearing aid recipients' partners.

Benefit and Quality of Life After Bone-Anchored Hearing Aid Fitting in Children With Unilateral or Bilateral Hearing Impairment

To evaluate the benefits of a bone-anchored hearing aid (BAHA) in the daily lives of hearing-impaired children. Retrospective questionnaire study. Nijmegen Medical Centre, Nijmegen, the Netherlands. 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. Scores on the Glasgow Children's Benefit Inventory, Abbreviated Profile of Hearing Aid Benefit, and Health Utilities Index Mark 3. The Glasgow Children's 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. Overall, BAHA fitting can be considered effective and beneficial in children with bilateral or unilateral hearing loss.

Technology-Limited and Patient-Derived Versus Audibility-Derived Fittings in Bone-Anchored Hearing Aid Users: A Validation Study

Current approaches to fit bone-anchored hearing aid (Baha) rely heavily on patient feedback of "loudness" and "sound quality." Audiologists are limited to this approach for two reasons: (1) the technology in current models of Baha does not allow for much fine-tuning of frequency response or maximum output on an individual basis and (2) there has not been a valid approach to verify the frequency response or maximum output on an individual basis. The objectives of this study are to (1) describe an alternative approach to fit Baha, an "audibility-derived (AD)" fitting, and (2) test whether outcomes improve with this new fitting compared with the current "patient-derived (PD)" fitting. This study used a repeated measures design where each subject experienced both the AD and PD fittings in random order. Subjects were tested on a variety of outcome measures including output levels of aided speech, hearing in noise test (quiet and in noise), consonant recognition in noise, aided loudness, and subjective percentage of words understood. Electromechanical testing revealed significantly higher aided output with the AD fitting, especially in the high frequencies. Subjects performed significantly better in all outcome measures with the AD fitting approach except when testing aided loudness and subjective perception for which the differences were nonsignificant. When the input levels to the Baha were soft, advantages for the AD fitting were emerging on these tests, but they did not reach significance. This study presents a more objective, fitting approach for Baha that leads to better outcomes in the laboratory. The next steps will be to test these fittings in the real world and to make the approach generally available to clinicians fitting Bahas.

Benefit and Quality of Life in Older Bone-Anchored Hearing Aid Users

Benefit and quality-of-life analysis in the older adult bone-anchored hearing aid (BAHA) users. Retrospective evaluation. Four questionnaires (Glasgow Benefit Inventory, Abbreviated Profile of Hearing Aid Benefit [APHAB], Nijmegen Cochlear Implant Questionnaire [NCIQ], and the Hearing Handicap Inventory for the Elderly screening version [HHIE-S]) were used. The response rate was 80%, mean age was 75 years (range, 62-93 yr), and mean pure-tone average at frequencies of 500, 1,000, 2,000, and 4,000 Hz for bone conduction was 42 +/- 13 dBHL. More than 80% of the patients were using their BAHA for more than 8 hours a day. To obtain a "snapshot" of current BAHA use, the NCIQ, HHIE-S, and the APHAB were used. The NCIQ showed good disability and handicap results (score range, 49-64). The HHIE-S showed that 60% of the patients had a mild to moderate handicap. The APHAB aided scores ranged from 39 to 58%. Mean benefit scores of the Glasgow Benefit Inventory were positive in 112 of the 134 patients (84%). The APHAB showed clinically significantly more benefit with the BAHA than with the previous aided or unaided situation. A trend could be seen-the higher the pure-tone average at frequencies of 500, 1,000, 2,000, and 4,000 Hz for bone conduction, the smaller the mean benefit scores on the questionnaires. Bone-anchored hearing aid users aged 60 years or older were able to place and handle the device very adequately and clean the skin around the implant. Most patients reported comparable or increased general benefit and good quality of life with the BAHA.

Bone-Anchored Hearing Aids

To investigate correlations between preoperative hearing thresholds and postoperative aided thresholds and speech understanding of users of Bone-anchored Hearing Aids (BAHA). Such correlations may be useful to estimate the postoperative outcome with BAHA from preoperative data. Retrospective case review. Tertiary referral center. : Ninety-two adult unilaterally implanted BAHA users in 3 groups: (A) 24 subjects with a unilateral conductive hearing loss, (B) 38 subjects with a bilateral conductive hearing loss, and (C) 30 subjects with single-sided deafness. Preoperative air-conduction and bone-conduction thresholds and 3-month postoperative aided and unaided sound-field thresholds as well as speech understanding using German 2-digit numbers and monosyllabic words were measured and analyzed. Correlation between preoperative air-conduction and bone-conduction thresholds of the better and of the poorer ear and postoperative aided thresholds as well as correlations between gain in sound-field threshold and gain in speech understanding. Aided postoperative sound-field thresholds correlate best with BC threshold of the better ear (correlation coefficients, r2 = 0.237 to 0.419, p = 0.0006 to 0.0064, depending on the group of subjects). Improvements in sound-field threshold correspond to improvements in speech understanding. When estimating expected postoperative aided sound-field thresholds of BAHA users from preoperative hearing thresholds, the BC threshold of the better ear should be used. For the patient groups considered, speech understanding in quiet can be estimated from the improvement in sound-field thresholds.

Age-Related Use and Benefit of the Bone-Anchored Hearing Aid Compact

To study age-related patient satisfaction with the bone-anchored hearing aid (BAHA) compact. A retrospective postal questionnaire, the International Outcome Inventory for Hearing Aids (IOI-HA), was sent to 211 BAHA Compact users. Questionnaire responses from 135 BAHA users were analyzed related to age, sex, years of BAHA experience, and the hearing thresholds (pure-tone average) at the aided side. Age ranged from 18 to 77 years. The IOI-HA showed that the BAHA Compact was greatly appreciated by almost all of the users: most patients stated that they were using the device for most of the day; it helped them to hear better and it reduced the number of situations in which hearing impairment was problematical. The cumulative score on the questionnaire was negatively influenced by age (rho = -0.191, p = 0.05). Furthermore, increase in sensorineural hearing loss (SNHL) component was associated with decrease in total IOI-HA scores (Spearman rho = -0.193, p < 0.05). A significant correlation was found between age and the SNHL component (Spearman rho = 0.525, p < 0.001).There were no significant differences in the levels of difficulty with placing the BAHA on the implant or with handling the BAHA between the age groups. Cleaning the skin around the implant causes the most difficulties in the youngest age group (p < 0.02). The BAHA Compact enhances participation in various domains of communication. Differences in patients' satisfaction seemed to be correlated with the SNHL component rather than age.

The bone-anchored hearing aid in children: A surgical and questionnaire follow-up study

The main objectives were to evaluate the surgical techniques and problems seen in children with bone-anchored hearing aids (BAHA) as well as to determine the children's attitudes toward BAHA. A retrospective study of 41 children with unilateral BAHA was conducted. Surgical recordings were investigated and a questionnaire was distributed. Surgery was performed as a 2-stage procedure. Available bone thickness was measured in 29 patients and found to be on average 2.5 mm. Thin temporal bone necessitated bone augmentation in 8 patients. Of the implants, 70.5% were installed in contact with the dura or the sigmoid sinus. Implant failures were seen in 9.1% and adverse skin reactions appeared in 7.6% of the patients. Twenty-seven patients responded to the questionnaire, 19 were still BAHA users. Overall, these patients were very content with their BAHAs. BAHA is a good alternative in children despite limited thickness of the temporal bone.

Evolving applications in the use of bone-anchored hearing aids.

The bone-anchored hearing aid (BAHA) is an effective means of intervention, its use being well documented in persons with chronic conductive pathology and congenital aural anomalies. This article describes the standard guidelines (both auditory and extraauditory aspects) for patient selection and expands the criteria to include bilateral BAHA implantation, unilateral conductive hearing loss, and unilateral profound sensorineural hearing loss. The BAHA's development, design features, and patient outcomes are also reviewed. Suggestions are presented for fitting, counseling, and following BAHA users.

Estimation of the Benefit of Bone-Anchored Hearing Aids

Implantable bone conduction hearing aids are a valuable alternative to conventional aids for those who cannot use a conventional air conduction aid or find it difficult to use because of an aural discharge, most commonly due to chronic otitis media. Previously reported series of the use of a bone-anchored hearing aid (BAHA) come from the originators of this device, and an independent report of their benefit and use, especially in previous air conduction aid users, would be of value. Twenty-three patients were evaluated at least 6 months after implantation of a BAHA. All 7 previous bone conduction aid users were delighted with their BAHA, reporting increased comfort and hearing benefit that was backed by audiometric evidence. Of the 16 individuals who previously used an air conduction aid, 11 (69%) were delighted users of their BAHA. Unfortunately, the other 5 (31%) reverted to solely using their air conduction aid. There was no obvious predictor as to how these individuals might have been identified prior to implantation. In particular, their pure tone thresholds, especially the bone conduction thresholds, were no different from those of the 11 BAHA users. However, in free field audiometry, the users gained superior benefit from their BAHA compared to their air conduction aid, whereas the nonusers did not. In conclusion, in all series to date, previous users of a conventional bone conduction aid have been delighted users of a BAHA and have gained superior audiometric benefit. This is not necessarily the case with previous air conduction aid users.(ABSTRACT TRUNCATED AT 250 WORDS)