Results of the bone-anchored hearing aid in unilateral hearing loss

OBJECTIVES: The advantages of binaural hearing are well established and universally accepted. However, a tendency remains to withhold the benefits of binaural hearing to adults and children with one normal ear. The purpose of this study is to demonstrate the benefit of the bone-anchored hearing aid (BAHA) in a group of patients with unilateral conductive or mixed hearing loss. STUDY DESIGN: This is a prospective study of nine patients (five males and four female patients) with conductive or mixed hearing loss who met the criteria for BAHA except for having normal hearing in the other ear. They had congenital aural atresia or mastoidectomies secondary to chronic ear infections with or without cholesteatoma or had a temporal bone tumor excised METHODS: Patients had evaluations before and after implantation, including audiological testing and responses to a standardized hearing handicap questionnaire. Statistical analyses of the data were made using the Wilcoxon signed rank test and the paired Student t test for repeated measures. RESULTS: All patients had tonal and spondee threshold improvement with BAHA when compared with thresholds before treatment. Speech recognition performance in BAHA-aided conditions was comparable to the patient's best score in unaided condition. Patients reported a significant improvement in their hearing handicap scores with the BAHA. CONCLUSIONS: The use of BAHA has significantly improved the hearing handicap scores in patients with unilateral conductive or mixed hearing loss. The proven safety and efficacy of the device promote its use in unilateral cases that traditionally had been left unaided.     

The super-bass bone-anchored hearing aid compared to conventional hearing aids. Audiological results and the patients' opinions.

Twelve patients with severe mixed hearing loss (PTA ranging from 70 to 108 dB HL) were provided with the percutaneous 'super-bass HC 220' bone-anchored hearing aid (BAHA) to replace their former hearing aid. Five had previously worn an air-conduction hearing aid (behind-the-ear type, BTE) which could no longer be used because of recurrent otorrhoea; the others had previously worn a conventional (transcutaneous) bone-conduction hearing aid (CBHA) which had caused serious complaints, such as headaches or skin irritation. Free-field speech audiometry in the subgroup of patients who used to wear a CBHA revealed that the maximum intelligibility score with the BAHA was equal to or better than that obtained with the CBHA (range from 0 to +27%). In three of the five patients who used to wear a BTE, the speech scores were poorer with the BAHA than with the BTE (range from -13 to -40%). For the remaining two patients, the difference in scores was 0 and +10%. In conclusion, speech recognition with the BAHA HC220 in the patients with severe mixed hearing loss was comparable to, or better than, that with a CBHA. Compared to an air-conduction hearing aid, the results may be considerably poorer. The results of the questionnaire were in good agreement with the measurements and support the conclusions.     

Comparison of audiological performance bewteen bone-anchored and conventional hearing aids

The bone-anchored hearing aid (BAHA) is an implantable bone-conduction device that vibrates the skull directly via a surgically implanted titanium screw behind the ear. The BAHA has advantages for patients with aural atresia or chronic ear drainage, who cannot wear air-conduction hearing aids. We compared the function of BAHA to conventional bone and air-conduction hearing aids based on functional gain and speech discrimination tests in quiet and noisy environments in 2 patients with chronic ear problems. All expressed a clear preference for the BAHA over conventional bone-conduction hearing aids. The BAHA and air-conduction hearing aid provided similar audiological performance when the functional gain of each hearing aid coincided. As the air-bone gap widens, however, audiological performance with the BAHA showed an evident preference, indicating that the width of the air-bone gap is of some help in BAHA preference compared to air-conduction hearing aids.     

Long-term results of bone-anchored hearing aid recipients who had previously used air-conduction hearing aids

OBJECTIVE: To study the long-term results (use, care, satisfaction, ear infections, and audiometry) of the application of a bone-anchored hearing aid (BAHA) to patients with conventional indications who had previously used air-conduction hearing aids. DESIGN: Follow-up study (mean duration, 9 years). SETTING: Tertiary referral center. PATIENTS: The study population comprised 27 patients with conductive or mixed hearing loss and who had participated in a previous study (N = 34). Seven could not be included anymore as a result of death, Alzheimer disease, or problems related to the implant. Everyone filled out the questionnaire, and 23 patients underwent audiometric evaluation. MAIN OUTCOME MEASURES: The patients filled out the adapted Nijmegen questionnaire. Aided free-field thresholds were measured as well as scores for speech in noise and in quiet. Results were compared with those obtained in the initial study. RESULTS: All 27 patients were still using their BAHA and appreciated it with regard to speech recognition in quiet, sound comfort, and improvements in ear infections. The audiometric results showed that most patients tested had stable bone-conduction thresholds over the years (after correction for age). Despite the treatment with BAHA, a significant deterioration in the cochlear hearing was observed in the other patients in the ear under study (their best hearing ear). CONCLUSIONS: Positive patient outcome measures emphasized the importance of BAHA application to patients with conventional indications. The audiometric data showed fairly stable cochlear function but not for all patients. This underlines that conservative treatment should be chosen (fitting of bone-conduction devices).     

The bone-anchored hearing aid: quality-of-life assessment

OBJECTIVES: To assess the impact of a bone-anchored hearing aid (BAHA) on the quality of life (QOL) of adults and to test the hypothesis that a BAHA improves QOL because otorrhea and/or skin irritations decrease. DESIGN: Prospective postal-based questionnaire study using validated health-related QOL instruments, combined with hearing-aid-related questions. PATIENTS AND METHODS: The study included 56 consecutive adult patients with acquired conductive or mixed hearing loss who were scheduled for BAHA implantation at the University Medical Centre Nijmegen, Nijmegen, the Netherlands. All 56 patients completed the 36-Item Short-Form Health Survey (SF-36), the EuroQol-5D (EQ-5D), and the Hearing Handicap and Disability Inventory (HHDI); 36 patients had been using an air-conduction hearing aid (ACHA) and 20 patients a conventional bone-conduction hearing aid (CBHA). Questionnaires were filled out before surgery and after 6 months of experience with the BAHA. RESULTS: In the SF-36 group, there was significant improvement in the scores of the mental health domain (P =.02). When the SF-36 patients were classified according to previous hearing aid, there was no statistically significant change in the scores in any of the domains. In the EQ-5D group and in its ACHA and CBHA subgroups, there were no important differences in the results before and after the patients received their BAHAs. In the HHDI group, the handicap and disability scales showed significant improvement (P<.01) irrespective of the type of previously worn hearing aid. CONCLUSIONS: Overall, generic health-related QOL was not influenced significantly by the use of a BAHA according to the SF-36 and the EQ-5D. The more disease-specific scales (HHDI) did show improved QOL with a BAHA.     

Fitting range of the BAHA Cordelle

The performance of the most powerful Bone-Anchored Hearing Aid (BAHA) currently available, the BAHA Cordelle, was evaluated in 25 patients with severe to profound mixed hearing loss. Patients showed bone conduction thresholds at 500, 1000 and 2000 Hz, ranged between 30?and 70 dB HL, and an additional air-bone gap of about at least 30?dB. With the BAHA Cordelle, free-field thresholds improve relative to bone-conduction thresholds with 1.5, 5.0, 17.8, and 4.3 dB at 500, 1000, 2000, and 4000 Hz, respectively, with substantial inter-individual variability. The differences in unaided air conduction thresholds and aided free-field thresholds amount to 45.3, 45.8, 47.5, and 43.5 dB at 500, 1000, 2000, and 4000 Hz, respectively. Speech perception, measured both with monosyllables of the consonant-vowel-consonant type and with bisyllables, showed highly similar results. The fitting range of a (linear) hearing aid is determined by its gain characteristics. Requiring aided speech reception thresholds at or better than 65 dB SPL results in an upper limit of the fitting range of the BAHA Cordelle for bone-conduction thresholds of 51, 56, 67, and 58 dB HL at 500, 1000, 2000, and 4000 Hz, respectively. The dynamic range provided by the BAHA Cordelle was estimated from loudness growth functions at 500, 1500, and 3000 Hz employing 7-point categorical scaling. On average, aided loudness growth functions exhibit normal slopes but they level off at input levels of about 80, 70, 65 dB SPL for 500, 1500, and 3000 Hz stimuli, respectively. Measurements with a skull simulator demonstrated that the levelling-off reflects saturation of the output of the Cordelle. The relatively low saturation levels of the device suggest that increasing maximum output levels may be a worthwhile consideration for candidates with more profound sensorineural loss.     

An intra-individual comparison of the previous conventional hearing aid with the bone-anchored hearing aid: The Nijmegen group questionnaire

By spring 2000, a total of 351 patients were implanted in the Birmingham bone-anchored hearing aid (BAHA) programme. This group consisted of 242 adults and 109 children. The aim of this retrospective questionnaire study was to directly assess patient satisfaction with their current bone-anchored hearing aid in comparison with their previous conventional air and/or bone-conduction hearing aids. The Nijmegen group questionnaire was sent by post to 312 patients who used their BAHA for six months or longer. The questionnaire used was first described by Mylanus et al. (Nijmegen group) in 1998. The total response rate was 72 per cent (227 of 312 patients). The bone-anchored hearing aid was found to be significantly superior to prior conventional hearing aids in all respects.     

Rehabilitation of patients with conductive hearing loss and moderate mental retardation by means of a bone-anchored hearing aid.

OBJECTIVE: To evaluate whether the bone-anchored hearing aid (BAHA) can be applied successfully to patients with conductive hearing loss and moderate mental retardation. STUDY DESIGN: Retrospective clinical evaluation. SETTING: Tertiary referral center. PATIENTS: Twenty-two patients with congenital moderate mental retardation and conductive or mixed hearing loss were selected to receive a BAHA at the University Medical Centre Nijmegen, the Netherlands. Four of them were fitted despite a limited air-bone gap. INTERVENTION: Rehabilitative BAHA application. MAIN OUTCOME MEASURES: Implantation results, skin reactions, and audiological data were evaluated during a mean follow-up of 36 months. RESULTS: All the patients were still using the BAHA 7 days a week and for more than 8 hours a day after a follow-up period between 5 and 96 months. Two implants (9%) were lost due to insufficient integration but were reimplanted successfully. With the BAHA, mean free-field thresholds showed a clear mean improvement of 9 dB compared with the previous hearing aid. Considerable improvements in daily activities were seen in at least five patients. CONCLUSION: Moderate mental retardation should no longer be considered as a contraindication for BAHA application. Although implant loss was low, extra attention may be required from the personal care providers to maintain the percutaneous implant. The BAHA was well-accepted by the patients with moderate mental retardation and was being used for most of the day. Implementation of the BAHA as hearing aid treatment in patients with moderate mental retardation proved to be sufficiently effective and may have strongly positive effects on activities at school or at work.     

Hearing with the bone-anchored hearing aid (BAHA,HC 200) compared to a conventional bone-conduction hearing aid

Sixteen patients have been fitted with a standard bone-anchored hearing aid (HC 200), to replace their conventional bone-conduction aid. The average pure tone threshold at 0.5, 1 and 2 kHz varied from 35 to 75 dB HL, with a sensorineural component varying from 0 to 30 dB HL. The patients' performance with the bone-anchored aid was compared to that with the conventional bone-conduction aid in an acoustic-free field. The maximum phoneme score in quiet was 100% in most patients; in 6 patients, the score with the bone-anchored aid was better (range from 5 to 10%). The speech-in-noise ratio was significantly better in 11 patients (range from—1.4 to—8 dB). None of the patients had poorer results on either test with the bone-anchored aid. The improved speech recognition was ascribed to better performance of the hearing aid in the higher frequency range (above 2 kHz) and to relatively less distortion.     

Bone anchored hearing aid in children--prevention of complications

To report results with the bone anchored hearing aid (BAHA) in children. Retrospective medical record review. Tertiary care children's hospital. Fourteen children with microtia/aural atresia underwent BAHA surgery. Mean age was 5.8 years. Data were collected concerning age, diagnoses, surgery, success of implantation, hearing, complications use of BAHA, speech reception thresholds (SRT), complications BAHA surgeries and revisions. Fifteen implants were placed by the author in 13 children. Eleven of 13 (84.6%) children are successfully using BAHAs (one bilateral) with a mean post operative SRT of 18.5dB (range 14-25dB). Mean interval between first and second stages was 7.3 months (n=12). Three unilateral implants were placed by a different surgeon in a child with severe hemifacial microsomia who developed complications treated by the author. Complications included poor healing requiring removal of three implants in one child, recurrent cellulitis of flap requiring revision (n=4), loss of implant (n=2), tearing of flap with dermatome due to tenting by healing screw (n=1), thin skull necessitating multiple drilling sites (n=1). BAHA surgery has a high success rate in children. The following recommendations may decrease complications: (1) 6-month period between stages in children with thin skulls, (2) thin flap with scalpel when it is tented by healing screw or infiltrate flap with local anesthetic to balloon it prior to using the dermatome for second stage cases, and (3) create extremely thin flap to prevent cellulitis.     

Bone-anchored hearing aid: comparison of benefit by patient subgroups

OBJECTIVES/HYPOTHESIS: The osseointegrated bone-anchored hearing aid, using the Branemark system, is well established and has proven benefit. The aim was to study quality of life benefits within patient subgroups using the validated Glasgow Benefit Inventory (GBI). STUDY DESIGN: Retrospective questionnaire study. METHODS: Ninety-four consecutive patients were enrolled into the study. Mean patient age was 49 years, with a female-to-male ratio of 1.1:1. Patient subgroups were discharging mastoid cavities, chronic active otitis media, congenital ear problems, otosclerosis, and acoustic neuroma and other unilateral hearing losses. RESULTS: The response rate was 73%. The score for total benefit of bone-anchored hearing aid fitting for the entire group was +33.3 (95% confidence interval [CI], 25-42). Glasgow Benefit Inventory scores for each subgroup were all greater than +20. The congenital atresia group scored highest with +45 (95% CI, 28-61). Variation in benefit across the subgroups has been demonstrated. Fitting of BAHA following acoustic neuroma surgery was shown to be of benefit with a score of +22.2. General benefits scored highest in all subgroups compared with physical and social benefits. CONCLUSION: The study demonstrated the differences in benefit within patient subgroups. Its results can be used to give patients a predictive value at the time of preoperative counseling. The study identified congenital ear disorders as the group likely to obtain maximal benefit. Notably, for the first time, the study demonstrated the documented benefit of restoring stereo hearing to patients who have acquired unilateral hearing loss following acoustic neuroma surgery using a BAHA.     

传导性或混合性耳聋患者佩戴骨锚式助听器软带的预期效果

目的 研究分析传导性或混合性耳聋患者进行佩戴骨锚式助听器(BAHA)软带后的听力改善情况。方法 参与研究者62例, 在声场进行BAHA软带佩戴前后纯音听力测试及问卷调查, 了解患者佩戴BAHA后的听力情况及主观感受。结果 62例佩戴BAHA后0.25～4 kHz气导听力均得到了不同程度提高, 对声音的方向感及噪声下言语交流能力提高。结论 BAHA能改善传导性聋或混合性聋患者的听力。     

The bone-anchored hearing aid for children: recent developments

In 1984 the Bone-Anchored Hearing Aid, or BAHA, system was introduced. Its transducer is coupled directly to the skull percutaneously to form a highly effective bone-conduction hearing device. Clinical studies on adults with conductive hearing loss have shown that the BAHA system outperforms conventional bone-conduction hearing aids. Therefore, the next step was to apply the BAHA system in children with congenital or acquired conductive hearing loss. Reviewed data showed that, on average, such children benefited significantly more from the BAHA than from reconstructive surgery. Thus, BAHA application appears to be the best option to achieve normal communication and speech and language development in children with bilateral conductive hearing loss. However, in children under the age of three to four years, a conventional solution must be applied, e.g. a bone conductor with a transcutaneous coupling, because they are too young to undergo BAHA implant surgery. In the case of unilateral congenital conductive hearing loss, there is no convincing evidence in the clinical literature for early intervention. In summary, the BAHA system can be considered a new, indispensable tool for children with bilateral conductive hearing loss.     

The BAHA HC200/300 in comparison with conventional bone conduction hearing aids

A retrospective study was performed on 89 patients from a consecutive series who received a BAHA HC200/300 after having previously used conventional bone conduction hearing aids. The patients’ performance with the BAHA HC 200/300 was compared to their performance with conventional bone conduction hearing aids. The patients were divided into two groups, depending on the time of implantation (before or after May 1992). The patients in group 1 (long-term users) were asked to fill in a questionnaire, the same one as they had filled in at the initial BAHA fitting more than 5 years previously. The answers were compared to their original opinions and difference scores were calculated. The long-term clinical results from group 1 are also presented. Although they are encouraging, the patients’ opinion about the BAHA deteriorated somewhat over time. The audiometric results of group 2 were highly comparable with those of group 1. This confirms the positive results with the BAHA found in previous studies.     

Bone-anchored Hearing Aids in Unilateral Inner Ear Deafness

In nine patients with unilateral deafness and normal hearing in the contralateral ear, measurements of sound localization and speech perception were obtained before intervention, with a conventional contralateral routing of sound (CROS) hearing aid and later with a bone-anchored hearing aid (BAHA) implanted in the deaf ear. Sound localization did not show any differences between the three conditions. Speech perception using short, everyday sentences showed a reduction in the head-shadow effect of 2 dB for both the conventional CROS hearing aid and the BAHA in comparison to the unaided condition. Patients' real-life experiences of the three conditions were evaluated using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. The results showed a significant benefit with the BAHA in situations involving background noise and reverberation and a reduced aversion to loud sounds in comparison to the unaided and conventional CROS conditions.     

The implant-site split-skin graft technique for the bone-anchored hearing aid 1

We describe the technique of implant-site split-skin grafting for the bone-anchored hearing aid (BAHA). Twenty-five patients have undergone this procedure (20 adults and five children) since 1993 with a minimum follow-up of 1 year. Fifteen adults were operated upon as single stage surgery, all other cases (including all children) were performed in two stages. In four patients (16%) significant early graft inflammation was encountered which settled with outpatient treatment. In one the abutment had to be temporarily removed to allow the graft to settle. All patients now have a stable graft site. This surgical technique is straightforward and a separate graft donor site is avoided. It would appear this technique results in a stable BAHA graft site with low associated morbidity.     

The Bone-Anchored Hearing Aid for children: Recent developments

In 1984 the Bone-Anchored Hearing Aid, or BAHA, system was introduced. Its transducer is coupled directly to the skull percutaneously to form a highly effective bone-conduction hearing device. Clinical studies on adults with conductive hearing loss have shown that the BAHA system outperforms conventional bone-conduction hearing aids. Therefore, the next step was to apply the BAHA system in children with congenital or acquired conductive hearing loss. Reviewed data showed that, on average, such children benefited significantly more from the BAHA than from reconstructive surgery. Thus, BAHA application appears to be the best option to achieve normal communication and speech and language development in children with bilateral conductive hearing loss. However, in children under the age of three to four years, a conventional solution must be applied, e.g. a bone conductor with a transcutaneous coupling, because they are too young to undergo BAHA implant surgery. In the case of unilateral congenital conductive hearing loss, there is no convincing evidence in the clinical literature for early intervention.

In summary, the BAHA system can be considered a new, indispensable tool for children with bilateral conductive hearing loss.     

Bone-anchored hearing aid quality of life assessed by Glasgow Benefit Inventory

OBJECTIVE/HYPOTHESIS: The bone-anchored hearing aid (BAHA) is a well established mode of treatment and many studies show the audiological benefit, but none has assessed the benefit to the quality of life of patients. This study uses the validated Glasgow Benefit Inventory to quantify the changes in quality of life. STUDY DESIGN: Retrospective questionnaire study. METHODS: Sixty consecutive patients receiving treatment with BAHA were enrolled in the study. The male/female ratio was 1.26 to 1; mean patient age was 45 years. The most common indication was hearing loss secondary to mastoid disease and surgery followed by congenital atresia and chronic discharge from the ear. RESULTS: The response rate was 85%, which is high and adds weight to the results. The general benefit score was +34 (range, +27-+48), which is comparable to middle ear surgery but just below benefit from cochlear implantation. The social benefit was +21 (range, +12-+37) with only +10 (range, +2-+26) for the physical score. This pattern mirrors that reported for other ear interventions. Maximum benefit was noted in patients with congenital atresias followed by discharging mastoid cavities. CONCLUSION: This study is the first to demonstrate significant quality of life benefit from BAHA surgical intervention as measured by the Glasgow Benefit Inventory.     

Bilateral bone-anchored hearing aids (BAHAs): an audiometric evaluation

OBJECTIVES: Since the technique to implant bone-anchored hearing aids (BAHAs) with the use of osseointegrated implants was developed in 1977, more than 15,000 patients have been fitted with BAHAs worldwide. Although the majority have bilateral hearing loss, they are primarily fitted unilaterally. The main objective of this study was to reveal benefits and drawbacks of bilateral fitting of BAHAs in patients with symmetric or slight asymmetric bone-conduction thresholds. The possible effects were divided into three categories: hearing thresholds, directional hearing, and binaural hearing. STUDY DESIGN: Prospective study of 12 patients with bilateral BAHAs. METHODS: Baseline audiometry, directional hearing, speech reception thresholds in quiet and in noise, and binaural masking level difference were tested when BAHAs were fitted unilaterally and bilaterally. RESULTS: Eleven of the 12 patients used bilateral BAHAs on a daily basis. Tests performed in the study show a significant improvement in sound localization with bilateral BAHAs; the results with unilateral fitting were close to the chance level. Furthermore, with bilateral application, the improvement of the speech reception threshold in quiet was 5.4 dB. An improvement with bilateral fitting was also found for speech reception in noise. CONCLUSIONS: Overall, the results with bilateral fitted BAHAs were better than with unilaterally fitted BAHA; the benefit is not only caused simply by bilateral stimulation but also, to some extent, by binaural hearing. Bilateral BAHAs should be considered for patients with bilateral hearing loss otherwise suitable for BAHAs.     

Bone-anchored hearing aids (Baha) in congenital aural atresia: personal experience

Aims

Aural atresia is a congenital disease constituted by partial or complete lack of development of the external auditory canal, which is generally associated with malformations of the auricle and middle ear.Reconstruction of the auditory canal and correction of any deformities of the middle ear have yielded unpredictable results and variable functional outcomes, and there is a high rate of complications. Therefore, the use of bone-conduction hearing aids, such as the Baha, may represent a valid alternative for subjects who have conductive hearing loss with cochlear reserve that, as a rule, is fully conserved.The aim of this work is to reexamine our experience with the management of conductive and mixed hearing loss using the Baha system in children with bilateral aural atresia.

Methods

We examined 31 patients with bilateral congenital aural atresia in whom a Baha system had been implanted. The patients, 16 males and 15 females, were between 5 and 14 years of age (mean 8.7).The following parameters were assessed for each patient: mean preoperative air and bone conduction for frequencies between 0.5 and 4 kHz; mean preoperative threshold with conventional bone-conduction hearing aids; mean postoperative threshold with the Baha system; improvement in quality of life evaluated with the Glasgow Children's Benefit Inventory; rate and type of surgical complications.

Results

The mean preoperative air- and bone-conduction thresholds were 51.2 ± 12.5 and 14.1 ± 6.3 dB HL, respectively. The mean preoperative threshold with a conventional bone-conduction hearing aid was 29.3 ± 7.2 dB HL, and the mean postoperative threshold with the Baha system was 18.1 ± 7.5 dB HL. Quality of life improved for all operated patients.

Conclusions

The results of our study of the Baha system to treat patients with bilateral aural atresia were extremely satisfactory compared both with those of surgical reconstruction of the auditory canal and those of traditional bone-conduction hearing aids. Furthermore, great improvement was noted in quality of life, while the rate of complications was very low.Therefore, we are convinced that the Baha system is the treatment of choice for hearing loss due to bilateral congenital aural atresia.