Speech recognition with in-the-ear and behind-the-ear dual-microphone hearing instruments

The primary purpose of this study was to compare the overall listening benefit in diffuse noise provided by dual-microphone technology in an in-the-ear (ITE) hearing instrument to that provided by dual-microphone technology in a behind-the-ear (BTE) hearing instrument. Further, the study was designed to determine whether the use of the dual-microphone + the manufacturer's party response algorithm in the ITE and BTE hearing instruments provided listening benefit in diffuse noise over their respective omnidirectional microphone modes. Twenty-four adults with mild to moderately severe sensorineural hearing loss were evaluated while wearing binaural BTE and ITE hearing instruments. The results indicated that the dual-microphone + party response mode did provide significant benefit in diffuse noise for both the ITE (3.27 dB signal-to-noise ratio [SNR] improvement) and BTE (5.77 dB SNR improvement) hearing instruments relative to their respective conventional omnidirectional microphones. No significant difference in performance was found between the ITE and BTE hearing instruments when each device was in the dual-microphone + party response mode. It is concluded that the use of dual-microphone technology in both ITE and BTE hearing instruments can improve speech recognition in diffuse noise.     

高龄老年人验配全数字助听器与模拟助听器效果分析

目的比较高龄老年人配戴全数字助听器和模拟助听器的效果。方法在声场测听的条件下，本文对10名患感音神经性耳聋的高龄老年人(年龄80—90岁，平均84岁，男6人，女4人共11耳)，在裸耳情况下分别选配模拟耳背式助听器．全数字耳背式助听器并进行声场测听和问卷调查。结果高龄老年人配戴全数字助听器的效果优于模拟助听器。结论全数字助听器适用于患感音神经性耳聋的高龄老年人。     

Hearing in the elderly and hearing aids

Statistically progressive deteriorations in the population, due more to pathological impairments than to aging properly speaking, must be distinguished from presbycusis. The onset of auditive impairment varies with genetic factors. In a statistical audiometric study, it is found that the better the hearing of a subject before the impact of presbycusis, the better the chances are of maintaining hearing; the opposite applies in the case of major auditive deterioration. Loss of hearing due to presbycusis affects all frequencies. The elderly patient has a better social value of hearing in the phonetic test than that expected from tonal audiometry, except in the case of disorders of central auditive integration.     

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.     

Recognition of hearing aid orientation content by first-time users

PURPOSE: To examine how well hearing aid orientation (HAO) content is remembered immediately and 1 month after the HAO, and whether the ability to remember this information differs as a function of the audiologist providing the information, patient's age, degree of hearing loss, and prior knowledge of hearing aids. METHOD: A convenience sample of 100 older adults completed a multiple-choice test of hearing aid knowledge immediately following the HAO and 1 month later. Covariate and regression analyses were used to address the study purpose. RESULTS: On average, participants recognized 74% of the information immediately following HAO and 78% at 1 month. Hearing loss was associated with declining recognition for hearing aid use and care information immediately following HAO, whereas prior knowledge was associated with successful recognition. Participants who recognized more HAO content immediately also remembered more at 1 month. A difference in recognition of hearing aid information based on audiologist was suggested immediately following HAO, but there were no differences at 1 month. Ability to recognize HAO content was not related to age of participants. CONCLUSIONS: On average, participants recognized approximately 75% of the HAO content, which is encouraging from a clinical standpoint, providing support for the efficacy of the HAO and the time audiologists spend in completing it. Moreover, recognition of HAO content improved when tested at 1 month, suggesting audiologists may expect their patients to be aware of a majority of hearing aid use and care information following the hearing aid trial period.     

Earphone termination and the response of behind-the-ear hearing aids.

An investigation was carried out on the effects on hearing aid response of placing the earphone in the earmould rather than in the case of a behind-the-ear hearing aid. Results from a number of physical configurations are reported and discussed and it is shown that it is possible to achieve a considerable reduction in the height of frequency response peaks. On the basis of the research reported some specific recommendations are made about future aid design.     

A comparison of three types of earmoulds in elderly users of post-aural hearing aids

The objective of this study was to assess the ease of handling, comfort, and general effectiveness of three types of earmould in patients who, due to their age, could be expected to experience handling difficulties. The three mould types were, meatal tip, skeleton and skeleton with the 'top prong' removed. The results indicated that the skeleton with the top prong removed was the best in all contexts but one. It was easiest and quickest to fit and least likely to be badly fitted. Only in feedback control did it perform less well. It was concluded that it should be routinely used for elderly patients fitted with low gain hearing aids.     

In-the-canal hearing instruments. Benefits and problems for inexperienced users given minimal instruction.

The number of in-the-canal hearing instruments (ITC) distributed annually in our region is increasing. The purpose of this investigation, which included 300 persons, was to evaluate the problems and benefits reported by ITC users who had received a minimum of counselling. Another aim was to decide which factors to concentrate on when teaching local health personnel how to assist hard-of-hearing equipped with ITC. The results showed that 38% had operational difficulties, 63% had experienced untoward sound reception. However, almost 90% reported positive experiences and the overall result for more than 80% was good. Operational difficulties resulted mainly from insufficient instruction. A moderate degree of instruction at the check-up was both essential and beneficial. Untoward sound experiences were caused mainly by inadequate venting and/or inaccurately adjusted instruments, faults that could be easily dealt with. It is therefore essential to teach local health service personnel that clients initially reporting problems in using their ITC can in most cases have their problems solved, mainly by simple instruction and/or an adjustment of the ITC. Only when these measures have failed should other types of hearing instruments (HI) be tried. Local health service personnel should therefore be instructed not to accept initial rejection of ITC merely because of the small size of the instrument until further instruction has been given, and not proved successful.     

Hearing loss and hearing handicap in users of recreational firearms

This investigation sought to establish the prevalence of hearing loss and hearing handicap in a population of 232 recreational firearm users. Hearing handicap was calculated based on four methods using pure-tone threshold data from the American Academy of Ophthalmology and Otolaryngology, American Academy of Otolaryngology-Head and Neck Surgery, National Institute of Occupational Safety and Health, and American Speech-Language and Hearing Association in addition to the self-report Hearing Handicap Inventory for Adults-Screener (HHIA-S). Subjects (45 female and 187 male) ranging in age from 13 to 77 years (mean = 40 years, SD = 15.1) completed a short questionnaire regarding demographics and shooting practices followed by pure-tone air audiometry at Occupational Safety and Health Administration test frequencies of 500 to 6000 Hz. A total of 177 who exhibited varying degrees of hearing loss also received a face-to-face administration of the HHIA-S. Audiometric and HHIA-S results revealed that both high-frequency hearing loss and hearing handicap varied significantly as functions of age and occupation. Significant gender effects were observed audiometrically but not as a function of hearing handicap. HHIA-S scores varied significantly as a function of high-frequency (1000-4000 Hz) hearing loss. Correlation coefficients between the four different pure-tone methods of calculating hearing handicap and the self-reported HHIA-S were highest for pure-tone methods that do not employ 500 Hz in the calculation.     

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.     

听障老年人的助听器验配

目的探讨听障老年人助听器验配的方法和技巧。方法对112名受试者进行跟踪随访，客观记录他们使用助听器的感受，分析助听器验配方法和技巧对助听器效果的影响。结果老年人的行为认知和听觉反应能力极大地左右着助听器的配戴效果；气骨导听阈，舒适阈，不适阈、言语识别阈的检查和使用对于老年人助听器验配十分重要；低频部分的听力补偿要低于目标值，高频部分要略高于目标增益值；老年人助听器配戴的适应期平均为3个月；双耳配戴的效果明显优于单耳。结论完全按照助听器验配软件设计的程序给老年人验配助听器很难达到理想的效果，而验配经验、技巧和验配后的适应性训练在其中发挥着巨大的作用。     

A comparison of wind noise in four hearing instruments

Wind noise was measured in four behind-the-ear hearing instruments with different microphone openings. A silent airflow of 7 m/s was directed toward the ear of a Kemar head and the resulting wind noise was measured. The amplification was set to an insertion gain of 35 dB at 1.6 kHz. The wind noise amplitude at the position of the drum ranged from 84 to 97 dB(A). The hearing instrument with a partially covered microphone entrance proved best, whereas one with an open microphone entrance had the poorest performance. A reduction in wind noise of 6-17 dB could be achieved in all hearing instruments by using a simple windscreen made of Styrofoam. The windscreen affected the frequency response by less than 2 dB. By subtracting the insertion gain from the wind noise, an equivalent wind noise could be presented as a function of frequency. A considerable difference was found between the wind noise sensitivity in different hearing instruments. All could be improved by a windscreen without adversely affecting the frequency response.     

Hearing screening--aspects of epidemiology and identification of hearing impaired children

Mass screening of hearing in children is based on the concept of secondary prevention. In recognition of the importance of an early identification and intervention in children with congenital or early-acquired (i.e. neonatal period) hearing disability, numerous hearing screening programs have been introduced throughout the world. The devastating consequences of a congenital/early acquired hearing disability upon the speech, language, and social development of a child, and the estimated prevalence rates of at least 1-1.5/1000 live births of congenital permanent hearing impairment, represent an important health problem. The increase in the estimated prevalence of permanent hearing impairment in childhood, reaching at least 3.6-8.2% of live births at 5-9 years of age further emphasizes the importance of the problem. The delayed identification of children with congenital/early acquired hearing disability should result in the implementation of universal neonatal hearing screening, and the negative impact on the learning processes during school age from hearing impairment acquired throughout childhood seems to justify the introduction or maintenance of a hearing screening at school entrance. Implementation of efficient hearing screening programs throughout the neonatal period, infancy, or childhood should result in secondary prevention of this important health problem.     

Hearing and language ability in mild and moderate hearing impaired children

102 children (mean age-7 years 9 mo.) with mild and moderate perceptive hearing impairment who had neither any auditory training nor had used a hearing aid were studied. Mean hearing level was 51.9 dB. Our findings: (1) Speech discrimination score (SDS) correlated with the hearing level at 2, 4 and 1 kHz, in that order. In all patients, SDS gradually worsened to 60 dB before registering a sharp decline; SDS was better than in patients who had acute unilateral hearing impairment and similar audiogram patterns, especially in vowels. (2) Correlation existed between the rate of accurate articulation and hearing levels at 2 and 4 kHz; it improved with age but plateaued at around 8 years. In children with a high tone loss, distortion and confusion of fricatives, explosives, unvoiced affricates and postconsonantal vowel /i/ were marked besides articulation errors commonly attributable to normal speech development. (3) On the WISC and WISC-R intelligence scale, verbal intelligence score had little correlation with performance intelligence and was influenced by hearing levels at 2, 4 and 1 kHz, in that order. When the mean hearing level was over 40 dB, verbal intelligence was frequently below par. Performance intelligence grew worse with age. (4) Children with a mild hearing loss exhibited a slight delay in vocalizing the 1st word and combining 2 words together while in those with a moderate loss, the delay in combining 2 words was pronounced. In both mild and moderate hearing loss, verbal intelligence was low when there was a delay in the ability to vocalize two words together.     

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.     

Hearing aid gain and frequency response requirements for the severely/profoundly hearing impaired

The optimal frequency response slope, from the low frequencies (250 or 500 Hz) to 2000 Hz, was estimated for each of 46 severely or profoundly hearing-impaired adults. The estimates were derived from paired comparison judgments of speech filtered to simulate different frequency response conditions, from home trials and ratings of different tone settings of high-powered, behind-the-ear hearing aids, and for 28 subjects, from speech recognition testing. The estimated optimal response, expressed as the slope from 250 to 2000 Hz and as the slope from 500 to 2000 Hz, was compared with the response prescribed by the National Acoustic Laboratories (NAL) procedure and its relationship to audiometric variables was analyzed. Insertion gain was measured for the preferred volume setting with the best frequency response. Preferred gain was typically about 10 dB higher than the NAL prescribed gain. Considering these results in relation to other data, it appears that the "half-gain" rule ceases to apply when HTL exceeds about 70 dB. The estimated optimal frequency response agreed with the NAL response for some subjects but relatively more low frequencies were required for between a third and half of the subjects, depending upon how frequency response is expressed. Generally, more low frequencies were required if HTL at 2000 Hz exceeded 95 dB, whereas the NAL response was usually appropriate for other cases.     

Development of a multimedia educational programme for first-time hearing aid users: a participatory design

Objective: To develop content for a series of interactive video tutorials (or reusable learning objects, RLOs) for first-time adult hearing aid users, to enhance knowledge of hearing aids and communication.

Design: RLO content was based on an electronically-delivered Delphi review, workshops, and iterative peer-review and feedback using a mixed-methods participatory approach.

Study sample: An expert panel of 33 hearing healthcare professionals, and workshops involving 32 hearing aid users and 11 audiologists. This ensured that social, emotional and practical experiences of the end-user alongside clinical validity were captured.

Results: Content for evidence-based, self-contained RLOs based on pedagogical principles was developed for delivery via DVD for television, PC or internet. Content was developed based on Delphi review statements about essential information that reached consensus (≥90%), visual representations of relevant concepts relating to hearing aids and communication, and iterative peer-review and feedback of content.

Conclusions: This participatory approach recognises and involves key stakeholders in the design process to create content for a user-friendly multimedia educational intervention, to supplement the clinical management of first-time hearing aid users. We propose participatory methodologies are used in the development of content for e-learning interventions in hearing-related research and clinical practice.