Advantages of a new miniature hearing aid for mild to moderate hearing loss

OBJECTIVES/HYPOTHESIS: To evaluate the performance of a new, miniature, behind-the-ear hearing aid designed for individuals with mild to moderate high-frequency hearing loss who need an aid but are reluctant to try one. The aid is essentially invisible, leaves the ear canal open, and can be fit in less than 30 minutes without an ear impression. The cost is less than $500. STUDY DESIGN: A 4-week trial of the aid in 63 ears (62 subjects) with mild to moderate bilateral hearing loss. METHODS: A questionnaire was completed at the end of the study by each subject asking them to evaluate several features of the aid (cosmesis, comfort, understanding speech, amplification, and so forth) and to compare their unaided performance in quiet and in noise with the test hearing aid. A rating scale of 1 to 10 was used, with 10 being excellent and 1 poor. RESULTS: Subjective improvement in understanding speech in both quiet (5.8-->7.3) and noise (4.6-->5.9) occurred with the aid. Cosmesis, comfort, and appearance were highly rated (mean scores, > 8). CONCLUSIONS: This aid appears to have several features (comfort, cost, performance, and cosmesis) that make it ideal as a first aid for patients with mild to moderate losses.     

Digital hearing aids for high-frequency sensorineural hearing loss: preliminary experience with the RetroX device

CONCLUSIONS: The RetroX outer ear hearing aid seems to represent a means of overcoming problems with understanding speech in noise in patients with high-frequency sensorineural hearing loss (SNHL) without the need to wear conventional completely-in-the-canal (CIC) hearing aids, which are usually reported to annoy patients as a result of the occlusion effect. OBJECTIVE: To present preliminary data from a study carried out to compare the efficacy, in the same individual, of a standard digital CIC hearing aid and a new implantable outer ear canal device, the RetroX. MATERIAL AND METHODS: Three out of 15 adults affected by high-frequency SNHL who were candidates for auditory rehabilitation were evaluated by using speech audiometric tests in quiet and noise as well as a questionnaire shortly after use of a CIC hearing aid and the RetroX device, i.e. at 7 and 14 days. The efficacy of the RetroX was anticipated by testing all the subjects using a RetroX simulating system before starting the study protocol. RESULTS: In all three implanted patients, the RetroX provided better audiological benefit for speech understanding in noise. These findings were corroborated by the results of the questionnaire, which showed greater satisfaction with the RetroX, especially regarding the absence of the occlusion effect.     

Vibrant Sound Bridge System. A new kind hearing prosthesis for patients with sensorineural hearing loss. 2. Audiological results

OBJECTIVE: Implantable hearing aids present a new treatment modality for patients suffering from sensorineural hearing loss. The functional gain obtained with the partially implantable Symphonix soundbridge system was evaluated in a clinical study. The audiological results achieved with n = 34 patients over a period of up to three years are presented in this second part of the publication. PATIENTS AND METHODS: 34 patients have received the Symphonix Vibrant soundbridge system since February 1997. The average age at implantation was 47.2 years (minimum: 18.9 years; maximum: 80.3 years). All patients have had several years of experience with hearing aids, which, however, provided insufficient functional gain or could not be fitted with a conventional hearing aid for medical reasons (such as auditory ear canal problems). All patients fulfilled the audiological selection criteria as they had bilateral moderate to severe sensorineural hearing loss. As a rule, the ear with poorer performance was implanted. All patients were fitted with the audio processor eight weeks after the implantation. The pure tone thresholds, the functional gain, the monosyllable and sentence understanding (G?ttinger Sentence Test in quiet and noise) were preoperatively and postoperatively assessed. Standardized self-assessment questionnaires were used to evaluate the subjective benefit (PHAB) and the quality of hearing (HDSS) as compared to the preoperative situation. Further hearing tests were performed after four weeks, three, six, nine, twelve, eighteen, twenty-four and thirty-six months postoperatively. During the observation period of up to three years the audioprocessor was updated several times, most recently with the fully digital three-channel-system Vibrant D. The results obtained were documented. RESULTS: Postoperatively, the pure tone threshold with the soundbridge system switched off did not change significantly in the implanted ear. All patients had a functional gain that was either comparable to the gain achieved with hearing aids or better. In particular speech-related frequencies showed improved amplification. The free field speech recognition tests revealed higher scores in quiet and in noise. The patients commended the natural sound quality, the lack of feedback, the absence of occlusion and distortion, the improved speech understanding in noise and the favourable cosmetic appeal. Only two patients failed to achieve better results as compared to their performance with conventional hearing aids. No complications, such as a deterioration of hearing due to inner ear damage or a conductive hearing loss, were observed in the long-term. CONCLUSIONS: The Symphonix Vibrant Soundbridge is a new and promising treatment modality for patients suffering from moderate to severe sensorineural hearing loss. Further improvement of the good results can be expected with improved coupling of the transducer to the ossicular chain and further development of signal processing.     

Characterization of side population (SP) cells in murine cochlear nucleus

Conclusions. The RetroX® outer ear hearing aid seems to represent a means of overcoming problems with understanding speech in noise in patients with high-frequency sensorineural hearing loss (SNHL) without the need to wear conventional completely-in-the-canal (CIC) hearing aids, which are usually reported to annoy patients as a result of the occlusion effect. Objective. To present preliminary data from a study carried out to compare the efficacy, in the same individual, of a standard digital CIC hearing aid and a new implantable outer ear canal device, the RetroX. Material and methods. Three out of 15 adults affected by high-frequency SNHL who were candidates for auditory rehabilitation were evaluated by using speech audiometric tests in quiet and noise as well as a questionnaire shortly after use of a CIC hearing aid and the RetroX device, i.e. at 7 and 14 days. The efficacy of the RetroX was anticipated by testing all the subjects using a RetroX simulating system before starting the study protocol. Results. In all three implanted patients, the RetroX provided better audiological benefit for speech understanding in noise. These findings were corroborated by the results of the questionnaire, which showed greater satisfaction with the RetroX, especially regarding the absence of the occlusion effect.     

Multiple-channel non-linear power hearing instruments for children with severe hearing impairment: long-term follow-up

The long-term benefits of multiple-channel non-linear technology for children with severe hearing impairment have yet to be fully investigated over the longer term. Twenty-one children with severe hearing loss participated in a study comparing performance on measures of audibility, speech understanding (in quiet and noise) and listening situations between the children's current analog hearing aids and a test hearing aid with multiple-channel non-linear compression (DigiFocus II Compact Power). Results were obtained from the children at 2 weeks, 8 weeks, 6 months and 12 months following the fitting of a multiple-channel non-linear hearing instrument. Compared with the children's own hearing instruments, the test instruments provided improved audibility, improvement in speech understanding in quiet and noise, and an improvement in listening skills. The gains in speech understanding were greater in noise than in quiet, suggesting that the test hearing instrument provided greatest improvement when listening to speech in noise. While performance increased over time, there was no statistically significant evidence to support continued acclimatization.     

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.     

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.     

Untersuchung von Faktoren bei der Erstversorgung mit Hörgeräten

OBJECTIVE: Systematic research on factors before the provision of hearing aids is scarce. In order to identify parameters which promote or impede the use of hearing aids, a questionnaire-based survey was conducted. SUBJECTS AND METHODS: A total of 35 randomly chosen, hard of hearing adults indicated for a hearing aid were examined. The importance of speech in quiet and in noise, wearing comfort, sound quality, appearance and costs, as well as expectations, willingness to use a hearing aid and reasons for and against provision were determined. RESULTS: Speech in noise and quiet were most important, followed by comfort of wearing and appearance of the aid. Expectations towards the hearing aids were in general high. The willingness to use hearing devices was positively affected by the expectation that it would improve quality of life and negatively by the amount of social activity of the person. The main reasons against the use of hearing aids were appearance and lack of confidence in hearing aid technology. CONCLUSIONS: This pilot-study identified several parameters which might affect willingness to use hearing aids. In particular, expectations towards the aids, personal attitude towards hearing and communication problems and the appearance of hearing aids should be subject to further examination.     

Clinical experiments with hearing aids with amplitude compression.

The model for audiological rehabilitation in Denmark is brief-described. Clinical experiments have not demonstrated a general superiority of the compression hearing aids compared to the conventional hearing aids. In situations with negligible background noise the compression hearing aid tends to provide the best comprehension of speech. However, in situations with background noise the conventional hearing aid is generally preferred by hearing impaired persons. The attitude with regard to compression hearing aids differs among Danish hearing clinics. One clinic with a very positive attitude delivers compression hearing aids to 27% of the total clientele. In several clinics it has been observed that patients with a perceptive impairment who are using the hearing aid for the first time may benefit from compression during the early stages of hearing aid adjustment. In many cases, however, these patients prefer less compression as they continue to use their hearing aids in daily life. It is pointed out, that in connection with compression hearing aids it is especially important to provide careful instruction about the possibilities and limitations of the hearing aid.     

Long-term functional outcome and satisfaction of patients with an active middle ear implant for sensorineural hearing loss compared to a matched population with conventional hearing aids

The objectives of the study were to review the results of an active middle ear implant for sensorineural hearing loss in patients who were unable to wear or did not benefit from conventional hearing aids in comparison to patients with a matched degree of hearing loss successfully fitted with a conventional hearing aid. A retrospective chart review of 10 patients (10 ears) after implantation of an active middle ear implant and 12 patients (13 ears) with conventional hearing aids in one tertiary referral center was performed. Intervention for sensorineural hearing loss was the implantation of an active middle ear implant in one group or fitting of conventional hearing aids in the other group. Outcome measures were pure-tone audiometry (auditory thresholds, functional gain), speech audiometry (Freiburg Monosyllabic Test in quiet and in noise) and a quality-of-life questionnaire (Glasgow Benefit Inventory). Average functional gain was 25.2 ± 8.6 and 14.6 ± 10.8 dB, speech recognition score in noise was 36.6 ± 18.4 and 31.2 ± 19.2 % and in quiet was 66.0 ± 23.2 and 61.5 ± 23.8 %, Glasgow Benefit Inventory total score was 38.3 ± 32.3 and 24.8 ± 22.2 in patients with active middle ear implants and conventional hearing aids, respectively. In two patient groups matched for degree of sensorineural hearing loss, active middle ear implants provided comparable speech recognition and superior functional gain and quality of life compared to conventional hearing aids. Level of evidence: 4     

Teilimplantierbare Hörgeräte bei Schallempfindungsschwerhörigkeit und kombinierter Schwerhörigkeit

In recent years semi-implantable hearing aids have become an established option in the treatment of sensorineural hearing loss. In Germany two semi-implantable systems are available, namely the MedEl Soundbridge system and the Otologics MET system, both of which are active middle ear implants. Since 1996 almost 3,500 Soundbridge systems and 300 MET systems have been implanted world-wide. The majority of patients who have received semi-implantable hearing aids consider them to be superior to conventional hearing aids in many respects. Reported benefits include improved speech intelligibility (especially in noise), better sound quality, a more natural sounding own voice and the general advantages of an open ear canal. Implantable hearing systems can be used for a wider range of indications than conventional hearing aids. They are particularly useful in the treatment of patients with high-frequency hearing loss and patients with combined hearing loss. An analysis of the hearing outcomes that have thus far been reported for all patients with a hearing implant shows an average improvement in the hearing threshold by 15 dB, which corresponds to an improvement in hearing of more than 30%. As a consequence semi-implantable hearing systems are an excellent addition to the existing range of conventional hearing aids.     

A comparison of behind-the-ear high-fidelity linear hearing aids and two-channel compression aids, in the laboratory and in everyday life

Eight patients suffering from sensorineural hearing losses with recruitment took part in a trial comparing their own hearing aids (or no aid if they did not normally wear one) with 'high-fidelity' linear aids and with aids incorporating two-channel syllabic compression. All aids were worn behind the ear. Speech intelligibility was measured both in quiet and in noise, and the patients were given questionnaires enquiring about the effectiveness of the aids in everyday situations. Both the intelligibility tests and the questionnaires indicated that the linear aids were substantially better than own/no aid, and the compressor aids were substantially better than the linear aids, allowing good speech discrimination over a wide range of sound levels. Six out of the eight patients derived significant benefit from being fitted with two aids rather than one. The use of directional microphones in the linear and compressor aids allowed a significant improvement for speech intelligibility in noise when the speech and noise were spatially separated.     

Multiple-channel non-linear power hearing instruments for children with severe hearing impairment: long-term follow-up

The long-term benefits of multiple-channel non-linear technology for children with severe hearing impairment have yet to be fully investigated over the longer term. Twenty-one children with severe hearing loss participated in a study comparing performance on measures of audibility, speech understanding (in quiet and noise) and listening situations between the children's current analog hearing aids and a test hearing aid with multiple-channel non-linear compression (DigiFocus II Compact Power). Results were obtained from the children at 2 weeks, 8 weeks, 6 months and 12 months following the fitting of a multiple-channel non-linear hearing instrument. Compared with the children's own hearing instruments, the test instruments provided improved audibility, improvement in speech understanding in quiet and noise, and an improvement in listening skills The gains in speech understanding were greater in noise than in quiet, suggesting that the test hearing instrument provided greatest improvement when listening to speech in noise. While performance increased over time, there was no statistically significant evidence to support continued acclimatization.     

Nonlinear digital hearing aid with near-instantaneous amplitude compression

We designed a new type of nonlinear digital hearing aid (TD-1) with near-instantaneous amplitude compression for sensorineural hearing-impaired people. The amplification method utilized by the TD-1 normalizes the signal waveforms within a time window bounded by two adjacent positive going zero-crossing points. The signals within this window are amplified so that the maximum amplitude reaches a preset value, thus allowing a consistent peak amplitude to be maintained. To test this, we examined the efficacy of the TD-1 device in 31 patients with sensorineural hearing loss. When tested for recognition of Japanese sentences in a quiet environment, 7 of 25 (28.0%) subjects wearing the TD-1 showed a 20% or greater increase in the maximum intelligibility score than that obtained when wearing their own linear hearing aids. In addition, 7 of 31 (22.6%) subjects showed the same increase with the TD-1 relative to that obtained when they wore HA70 or HA73 devices (Rion Co., Ltd., Tokyo, Japan), which are conventional analogue hearing aids. These results indicate that TD-1 can be effective for patients with sensorineural hearing loss. Received: 27 March 2001 / Accepted: 29 June 2001     

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.     

Benefit from,and acclimatization to,frequency compression hearing aids in experienced adult hearing-aid users

Objective: The aim was to investigate whether frequency compression (FC) hearing aids provide additional benefit to that conferred by conventional amplification. Design: Participants wore the same hearing aid with FC enabled and disabled for six weeks (ABA design) in each condition. Speech recognition tests (in both quiet and in noise) were administered alongside two questionnaires. Performance was compared across the two signal processing conditions and at different time points. Study sample: Twelve experienced hearing-aid users (aged 65–84 years old) with moderate-to-severe high-frequency hearing loss participated in the study. Results: FC resulted in statistically significantly higher mean scores in all of the administered speech tests. Improvements over time were limited to high frequency phoneme perception. No effect of FC on self-report outcomes was observed. Conclusions: FC may lead to significant improvements in speech perception outcomes in both quiet and noise for many individuals. No participant was significantly disadvantaged by the use of FC.     

Audiological effect of bone-anchored hearing aid

The bone-anchored hearing aid (BAHA) has proved to be a valuable alternative to conventional air and bone conduction hearing aids for patients suffering from chronic otitis media or bilateral aural atresia. The BAHA gave better sound quality and greater comfort than conventional hearing aids (HAs), but only 1 study has been done in Japan. We implanted BAHAs in 6 hard-of-hearing patients in the last 2 years. One patient suffered skin problems around the abutment and used the BAHA only briefly. Free-field audiometry, the speech discrimination test (SDT), and the speech recognition test (SRT) were conducted in all subjects. They were evaluated either with the HA or BAHA. The SDT and SRT showed better hearing results in quiet for the BAHA than the conventional HA, but there was a minimum difference in SDT and SRT in noise. Subjects assessed the HA and BAHA using questionnaires. Subjects reported that the BAHA offers a number of important advantages, including greater cosmetic acceptability, improved speech intelligibility, and better sound quality.     

New aspects of hearing aid fitting in noise-induced hearing loss

In the past hearing aid fitting frequently turned out to be a problem in patients with noise-induced hearing loss. Selective amplification in the high frequency range and at the same time natural sound and appropriate wearing comfort (open fitting) could not be achieved in numerous cases. Today these problems can be tackled by modern hearing aid technology providing us with efficient feedback suppression algorithms making open fittings possible for many more patients. This development is particularly beneficial for patients with noise-induced hearing loss. Unfortunately, open fitting is in opposition to wearing hearing aids at noisy workplaces. Tight fittings, however, can be used at work if a special listening program for noisy conditions is available. This dilemma is discussed and possible solutions are pointed out.     

Acclimatization in first-time hearing aid users using three different fitting protocols

OBJECTIVE: To study auditory acclimatization and outcome in first time hearing aid users fitted with state of the art hearing aids as a function of different hearing aid fitting protocols. METHODS: Twenty-eight adult subjects participated in the study. Each subject was assigned to one of three study groups (named audiologist driven, AD; patient driven, PD; set-to-target, STT according to the fitting protocol used) and fitted with digital hearing aids (Bernafon Symbio). Speech recognition scores were measured in aided and unaided conditions over a 6-month period. RESULTS: Five subjects (three from the PD-group, two from the STT group) decided to withdraw from the study during the 6-month-study period, leaving a total of 23 complete data sets for analysis. Aided speech understanding increased significantly over this time period in all three groups. However, average hearing aid insertion gain changes were small over the same period. There were no statistically significant differences in aided or unaided speech recognition scores between the three groups after 2 weeks or after 6 months. On average, twice as many fine tunings of the hearing aids were requested by the patients in the AD and the STT group than in the PD group and subjects in the AD and STT group used their hearing aids approximately twice as much as subjects in the PD group. CONCLUSIONS: The substantial increase in speech intelligibility without significant changes of the insertion gain of the hearing aids over a 6-month period in all three groups suggests a significant acclimatization effect. Although the speech recognition with hearing aids did not differ significantly among the three study groups after 6 months, the lower average wearing time and the higher number of withdrawals from the study in the PD group suggest that the patients' needs are not adequately met. In terms of aided speech recognition scores and hearing aid wearing time the STT group and the AD group were very similar. However, comments of the patients and the higher rate of withdrawals in the STT group suggest an over-all advantage for the AD fitting protocol.     

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.