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.     

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.     

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.     

Clinical results with a percutaneous bone-anchored hearing aid

During a 2-year period ending in July 1987, nine patients were implanted with a percutaneous bone-anchored hearing aid developed at the University of Gothenburg and Chalmers University of Technology, Sweden. Patient selection was based on the presence of conductive or mixed hearing loss in patients who are unable to wear a conventional hearing aid because of infection or ear canal problems. Patients had speech discrimination scores of at least 60% for phonetically balanced monosyllables (CID lists) at 40 dB above threshold, and a pure tone bone conduction average of 45 dB hearing loss or better. Patients were evaluated in sound field, preoperatively and postoperatively using warble tones, speech reception threshold, speech discrimination, and synthetic speech identification. The patient's unaided hearing and hearing with a bone-anchored hearing aid were compared with the patient's hearing with a standard bone conduction hearing aid. Signal to noise ratio testing with the synthetic speech identification test demonstrated that the bone-anchored hearing aid was comparable to a standard bone conduction aid. There were no complications in our series. Five patients who reported otorrhea with conventional hearing aids experienced no otorrhea after implantation. Patient satisfaction, as assessed by questionnaire, revealed that all patients preferred the bone-anchored hearing aid to previously worn hearing aids.     

Hearing aid use in Finnish children--impact of hearing loss variables and detection delay

OBJECTIVE: The aim was to study the factors contributing to the mode of hearing aid use in children, with special emphasis on hearing loss variables and detection delay. METHODS: The subjects were 328 children and adolescents (58.5% boys, 41.5% girls) aged 1-18 years with hearing loss of > or =30 dB HL in the better ear fitted with hearing aid(s). The study was cross-sectional analysing the mode of using the aid binaurally/unilaterally or not at all. RESULTS: The children with hearing-impairment ranging from 50 to 90 dB HL used more regularly their hearing aids. In the subjects with hearing loss > or =80 dB HL the presence of measurable hearing threshold at 4 kHz related significantly to the acceptance of amplification (p=0.027). In 19% of the subjects hearing aid was discarded. Bilateral amplification was used in 38%. Unilateral use was the prevailing mode (44%). The younger the children (p=0.000) and the worse their hearing loss (p=0.008), the more regular their bilateral use was. Early detection of hearing loss and early hearing aid fitting promoted binaural hearing aid use (p=0.004). A marked asymmetry in pure tone thresholds was a significant audiological reason for fixed unilateral hearing device use (38%, p=0.001). CONCLUSIONS: The study shows that early detection of hearing loss and early habilitation of hearing increase bilateral use of hearing device and decrease the number of nonusers. Furthermore, residual unaided hearing at 4 kHz significantly improves the use of device.     

Candidacy for the bone-anchored hearing aid

The BAHA (bone-anchored hearing aid) is a bone conduction hearing aid with percutaneous transmission of sound vibrations to the skull. The device has been thoroughly evaluated by various implant groups. These studies showed that, in audiological terms, the BAHA is superior to conventional bone conduction devices. In comparison with air conduction devices, the results are ambiguous. However, a positive effect is found with respect to aural discharge. The most powerful BAHA can be applied to patients with a sensorineural hearing loss component of up to 60 dB HL. It was shown that bilateral BAHA application leads to binaural sound processing. Preliminary results on the application of the BAHA in patients with unilateral conductive hearing loss suggest that stereophonic hearing can be re-established. The application of the BAHA as a transcranial CROS (contralateral routing of signal) device in unilateral deafness minimizes head shadow effects.     

有低频残余听力感音神经聋的人工耳蜗植入术

目的介绍一种有低频残余听力感音神经聋的人工耳蜗植入技术,探讨人工耳蜗植入手术对有残余听力患者的治疗效果和价值。方法15例有残余听力的患者接受了保护残余听力的人工耳蜗植入手术。术中电极植入深度在19mm～24mm左右。术后分别检测单纯使用助听器、单纯使用人工耳蜗、人工耳蜗结合助听器三种不同状态下的听力。结果15例患者中,有13例术后残余听力保存良好,仅分别丢失5～20dB听力,但另2例术后残余听力全部丧失。术后在安静、信噪比15dB和10dB三种不同状态下的言语测试结果显示,人工耳蜗结合助听器使用者测试得分始终保持在很高水平;单纯使用人工耳蜗者也有较好的成绩,但在信噪比达10dB的条件下,测试成绩下降;而单纯使用助听器者,不仅在安静状态下听力成绩不甚理想,一旦加入竞争性噪声,听力测试成绩急剧下降。结论保护和利用残余听力的人工耳蜗植入技术,使人工耳蜗植入手术对象从重度或极重度聋扩大到高频为重度或极重度聋,低频（≤500Hz）为中、轻度聋的患者。接受这项技术患者的听力和言语识别能力均明显优于其单纯配戴助听器和单纯使用人工耳蜗时的听力和言语识别能力。     

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.     

Audiological application criteria for implantable hearing aid devices: a clinical experience at the Nijmegen ORL clinic

Objectives/Hypothesis: To define audiological application criteria for different implantable hearing aid devices. Study Design: Retrospective study. Methods: Comparisons were made between aided speech recognition scores obtained at conversational level (65 dB) in patients with the Vibrant Soundbridge (VSB) (n = 22), the Otologics middle ear transducer (MET) (n = 10), conventional hearing aids (behind-the-ears) (n = 47), and cochlear implants (CIs) (n = 123). Results: In relation to hearing loss, only for mild hearing loss, speech recognition scores with VSB were comparable to that with conventional hearing aids. In the Otologics MET users, speech recognition scores were comparable with those of the conventional hearing aid users until a mean hearing loss of about 75 dB HL. At a sensorineural hearing loss of about 65 dB HL or more, the Otologics MET users have better speech recognition scores than the VSB users. For comparison with CI users, we followed a more conservative approach. In 90% of the users of a CI, speech recognition scores were better than those in: 1) patients with a conventional hearing aid and a mean hearing loss of about 95 dB HL or worse; 2) patients with an Otologics MET and a mean hearing loss of 85 dB HL or worse. Conclusions: Patients fitted with a VSB or an Otologics MET middle ear implant do not demonstrate better speech recognition scores than patients fitted with today's conventional hearing aids. Results might even been worse. However, the VSB and Otologics MET are a good option in patients with moderate (VSB) to severe (Otologics MET) sensorineural hearing loss and external otitis.     

Monosyllable speech perception of Japanese hearing aid users with prelingual hearing loss: implications for surgical indication of cochlear implant

OBJECTIVE: The monosyllable speech perception ability after years of educational intervention was compared between prelingually deafened pediatric hearing aid users and their cochlear implant counterparts. DESIGN: An open-set monosyllabic speech perception test was conducted on all subjects. The test required subjects to indicate a corresponding Japanese character to that spoken by the examiner. Fifty-two subjects with prelingual hearing impairment (47 hearing aid users and 5 cochlear implant users) were examined. RESULTS: Hearing aid users with average pure-tone thresholds less than 90 dB HL demonstrated generally better monosyllable perception than 70%, which was equivalent or better performance than that of the cochlear implant group. Widely dispersed speech perception was observed within the 90-99 dB HL hearing-aid user group with most subjects demonstrating less than 50% speech perception. In the cluster of >100 dB HL, few cases demonstrated more than 50% in speech perception. The perception ability of the vowel part of each mora within the cochlear implant group was 100% and corresponding to that of hearing aid users with moderate and severe hearing loss. CONCLUSION: Hearing ability among cochlear implant users can be comparable with that of hearing aid users with average unaided pure-tone thresholds of 90 dB HL, after monosyllabic speech perception testing was performed.     

Retrospective audiological analysis of bone conduction versus round window vibratory stimulation in patients with mixed hearing loss

Objective: To compare audiological outcomes in mild-to-moderate mixed hearing loss patients treated with a bone-anchored hearing aid or an active middle-ear implant. Analysis aimed to refine criteria used in preoperative selection of implant type. Design: Retrospective comparative analysis of audiological data. Follow-up time ranged between 0.55 and 8.8 years. Study sample: For detailed comparative analysis, 12 patients (six in each group) with comparable bone conduction thresholds and similar clinical characteristics were selected. A larger cohort of 48 patient files were used to evaluate overall audiological indication criteria (24 per group). Results: In free-field tone audiometry, Baha patients showed mean aided thresholds between 40–48 dB, whereas hearing thresholds for VSB patients were 25–43 dB. Baha and VSB users had mean WRS of 56% and 82%, respectively, at 65 dB. Better speech understanding in noise was seen with the VSB. Conclusion: Analysis of the main cohort (n = 48) showed that treatment with round window vibroplasty leads to better hearing performance than treatment with a bone-anchored hearing device, if the bone conduction pure-tone average (0.5 to 4 kHz) is poorer than 35 dB HL. Audiological analysis in the smaller comparative analysis showed similar findings.     

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.     

Clinical study of Widex Senso on first-time hearing aid users.

Using psychoacoustic tests and questionnaires, the aim of this study was to clinically test Widex Senso (WS) versus analogue hearing aids on 200 first-time wearers. Half of the participants were selected at random for fitting with the behind-the-ear model (WS C8) or the in-the-canal model (WS CX). On a group basis, WS was found to provide more benefit than a palette of 29 analogue, modern hearing aid models from 10 manufacturers. Only 3 of 100 subjects changed from WS to another hearing aid. On average, the abbreviated profile of hearing aid benefit (APHAB) (Cox & Alexander, 1995) demonstrated superior performance for WS, i.e. no conflict existed between high comfort and high speech recognition. Median aided frequency-modulated tone thresholds in the sound field were better than 25 dB HL at frequencies up to 4 kHz inclusive. A distinct mean aided improvement of speech threshold in competing speech of 2.5 dB was found in both groups.     

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).     

Prevalence of hearing impairment in a population in Sweden

An epidemiological study was carried out, based on 590 randomly selected subjects, aged from 20 to 80 years, in the province of Osterg?tland in Sweden. The results obtained were similar to published results from other countries, with an overall prevalence of subjects with average hearing threshold levels over the frequencies 0.5, 1, 2 and 4 kHz (M4) equal to or exceeding 25 dB HL for the better ear (BE) of 16.9% (95% CI: 13.819.9%). For M4 BE > or = 35 dB HL, the prevalence was 7.7% (95% CI: 5.5-9.8%), for M4 BE > or = 45 dB HL, the prevalence was 3.3% (95% CI: 1.9-4.8%), and for M4 BE > or = 65 dB HL, the prevalence was 0.2% (95% Cl: 0.0-0.6%). The overall prevalence of reported tinnitus was 13.2% (95% CI: 10.5-16.0%). In the population under study, 7.7% of the subjects were estimated to benefit from a hearing aid, while the prevalence of hearing aid users was 2.4%.     

Patient satisfaction with the bone-anchored hearing aid: a 14-year experience.

OBJECTIVES: To evaluate the self-rated quality of life (QoL) and benefits associated with the use of bone-anchored hearing aids (BAHAs) and to identify potential improvements in comparison to the previous conventional hearing aids. STUDY DESIGN: Cross-sectional. SETTING: BAHA program in tertiary referral center. PATIENTS: One hundred fifty-two adults who underwent BAHA procedure for more than 6 months. INTERVENTION: Rehabilitative. MAIN OUTCOME MEASURE: Results of the Entific Medical Systems questionnaire. RESULTS: One hundred seventeen responses (77%) were obtained. Overall satisfaction was excellent (median = 9). BAHA was rated very good/excellent in single-person conversation (85%), but fared less well in group situation (45%). BAHA was reported as better than the previous aid by more than 50% of patients within each subcategory where applicable (handling, 64%; comfort, 56%; cosmetic, 60%; sound, 68%; infections, 75%). Of those who reported improvement of ear infections, one quarter remained unsatisfied of improvement in QoL. Patients who used BAHA for 3 years or less (n = 45) had a similar rating to sound quality and conversation as those who used it longer (n = 72). Surprisingly, a subset of patients (n = 8) with poor bone-conduction thresholds (> 45 dB) remained satisfied with the device (median = 8). CONCLUSIONS: The BAHA can improve QoL and hearing outcome with full acclimatization to the device being achievable within a reasonable amount of time. As with conventional aids, sound quality in group situations remains poor with the BAHA. Our results provide a predictive value during preoperative counseling of patients.     

Population study of the ability to benefit from amplification and the provision of a hearing aid in 55-74-year-old first-time hearing aid users

About 40% of 55-74-year-olds have an impairment in at least one ear of 25+ dB HL, and 27% have bilateral impairment at this level, with 11% being impaired bilaterally at 35+ dB HL. Only 6% currently use a hearing aid. The performance of a random sample of participants aged 55-74 years on speech-in-noise tasks shows that significant statistical benefit was obtained from bilateral amplification in over 20% of the population who do not currently use a hearing aid. The offer of a hearing aid to all those who exceeded a 25 dB HL criterion in the worse car was accepted and taken up by 40%, with 16% declining and the remainder being excluded for pathological and logistic reasons (e.g. hearing loss profile not suitable for aid). This is a very high rate of 71% acceptance. One in four fitted with the hearing aid showed a statistical advantage for hearing speech in noise in freefield (noise and speech from in front) with the hearing aid. Thus at least 10% of the population who do not currently use an aid would benefit substantially from a hearing aid in a quiet speech-in-noise environment. Those with poorer cognitive function show greater benefit overall and less disadvantage in very bad signal-to-noise environments. The overall pattern of results support screening and providing hearing aids to those who do not currently have an aid(s), and suggests that there would be considerable population benefit. At least two main questions for further research remain: (1) would bilateral aiding strategies give greater benefit; and (2) would different hearing aids and fitting strategies be more appropriate for people with differing 'cognitive task' loadings on phonological memory and lexical decision factors?     

A bone-anchored hearing aid for patients with pure sensorineural hearing impairment: a pilot study

This pilot study assesses the potential benefits of an optimized bone-anchored hearing aid (BAHA) for patients with a mild to moderate pure sensorineural high frequency hearing impairment. The evaluation was conducted with eight first-time hearing aid users by means of psycho-acoustic sound field measurements and a questionnaire on subjective experience; all of the patients benefited from the BAHA. On average, the eight patients showed improvement in PTA threshold of 3.4 dB and in speech intelligibility in noise of 14%. Seven of the subjects, also fitted with present standard air conduction hearing aids (ACHA) found the ACHA thresholds to be improved more than the BAHA ones. In speech tests, the ACHA was only slightly better; these patients chose between their different hearing aids according to the sound environment. Although the BAHA was preferred for wearing and sound comfort, it cannot be used as the sole aid for patients with pure sensorineural impairment.