助听器的声场验配法

在声场测听条件下，对17名儿童（33耳）进行助听前和助听后的声场听阈测试。以助听后听阈值能否进入言语香蕉图范围来评价助听效果，为使助听效果满意，在测试时可调节助听器的各种调节使扭；测试结果显示，该法不失为助听器验配的有效方法之一。本文亦对影响本方法的一些因素做了讨论。     

游戏测听与听觉诱发脑干反应评估小儿听力

目的 通过对60例3～6岁感音神经性耳聋小儿听性脑干反应(auditory brainstem response,ABR)与小儿游戏测听(play audiometry,PA)测试结果比较,综合评估小儿听力.方法 选择60例3～6岁门诊患儿,均经声导抗测试及耳声发射测试排除传导性耳聋及听神经病,将60例3～6岁小儿120耳分别进行ABR测试.根据ABR测试结果.选择ABR波V反应阈为50～90 dB nHL的小儿30例为A组,ABR最大输出97 dB nHL未引出波V反应阚的小儿30例为B组;之后两组小儿分别进行游戏测听,将两组的ABR反应阈与游戏测听测试结果进行比较.结果 A组ABR的波V反应阈与小儿游戏测听中2 kHz～4 kHz最小听闻相差均无显著差异:B组ABR最大输出97 dB nHL未引出波V的小儿,游戏测听绝大部分均能获得行为听阈.结论 ABR的波V反应阈与小儿行为测听的高频听阈一致性较好;ABR最大输出97 dB nHL未引出波V的不等于无听力.     

Pediatric hearing aid evaluation: case reports

The Pediatric Speech Intelligibility (PSI) sentence materials were used to carry out hearing aid evaluations in one child who was too immature to be tested by conventional speech audiometric techniques and in a second child who completed both conventional and PSI procedures. Results indicated that the PSI sentence materials lower the age level at which hearing aid evaluations can be carried out via speech audiometry in young children.     

An evaluation of several rationales for selecting hearing aid gain

The present study evaluates the rationales underlying several hearing aid selection procedures. The first portion of the evaluation confirms that the gain-selection rationales result in the selection of different hearing aids for a given patient. Nine different audiometric configurations representing varying degrees of flat, sloping, and rising sensorineural hearing loss were considered. The second phase of the evaluation considered how well each procedure achieved the goal of maximizing speech recognition. This analysis made use of the Articulation Index and was applied to each of the nine audiometric configurations. The results of this analysis suggested that, given the ability to adjust the overall gain over a typical range available through most volume controls, any of the procedures could produce optimal aided speech recognition performance. The final portion of the evaluation examined the ability of each procedure to prescribe absolute gain and relative gain (frequency response) that corresponded to that preferred by hearing aid wearers. The data for preferred insertion gain came from a recent investigation by Leijon, Eriksson-Mangold, and Beck-Karlsen (1984). The results of this evaluation suggested that some procedures prescribe gain values closer to those preferred by listeners than others. More data are needed on preferred gain values for a variety of configurations, however, before any one procedure can be recommended over another.     

A new hearing aid variant. Preliminary evaluation

An attempt was made to combine the advantages of a behind-the-ear (BTE) hearing aid (trouble-free use, powerful amplification, room for high-quality components, space for large energy source, use of extra equipment), with the advantages of the in-the-ear (ITE) hearing aid (improved intelligibility, improved directional hearing, improved signal/noise ratio). A BTE hearing aid was equipped with filters and provided with an external microphone. A first experiment, carried out in an anechoic chamber on KEMAR (Knowles Electronic Manikin for Acoustical Research), showed that directional variation of the frequency response of the hearing aid microphone was better in the new hearing aid than in the original BTE. A second experiment was carried out with a group of 6 normal-hearing persons concerning the frequency characteristic of sound transmission from twelve angles in the horizontal plane without a hearing aid, with a normal BTE aid, with the 'new aid', and with an ITE aid. The new instrument gave significantly better directional hearing than the original BTE aid. A clinical study will be started to verify and extend the experimental results obtained.     

Frequency compression hearing aid for severe-to-profound hearing impairments

(1) Objective: Objective of this study is to know how a frequency compression hearing aid with new concepts is beneficial for severe-to-profound hearing impairments. (2) Methods: Clinical trials of this hearing aid were conducted for 11 severe-to-profound hearing impaired listeners. These 11 wore the frequency compression hearing aid in their daily life and reported subjectively on its performance. Speech recognition tests with five listeners and audio-visual short sentence recognition tests with three listeners were also conducted. This hearing aid can separately adjust the fundamental frequency from the spectral envelope of input speech and can adjust frequency response by use of a post-processing digital filter. (3) Results: Five listeners out of these 11 came to prefer this hearing aid in their daily life and are still wearing it. The results of the speech recognition tests show that the speech recognition scores were not improved for all listeners and the results of the audio-visual short sentence recognition tests do that the audio-visual recognition scores were improved for two listeners. (4) Conclusion: There were some severe-to-profound hearing impaired listeners who preferred the frequency compression hearing aid finally. It is also suggested that the benefits of this hearing aid may be evaluated correctly using not only speech but also visual materials.     

Clinical evaluation of a two-channel amplitude compression hearing aid

Twelve experienced hearing aid users with mild to moderate hearing loss used two new, commercially available behind-the-ear amplitude compression hearing aids for 1 month each. One aid was a single-channel device; the other was a two-channel aid. All subjects had used other compression aids for at least 1 year. Performance in real-life situations with the personal aid and the two trial aids was evaluated by the Hearing Performance Inventory (HPI). Another questionnaire probed subjective preference for the three aids and willingness to purchase each of the trial aids. The major HPI finding was an equal performance superiority for the two trial aids over the personal aid for half the subjects. The preference/purchase questionnaire results indicated that the two-channel aid had some sound quality advantages, but was unacceptable physically. The single-channel trial was clearly preferred over the personal and two-channel device.     

High-frequency audiometry and noise-induced hearing loss

A group of noise-exposed male subjects with an audiogram that is characteristic for noise trauma were submitted to high-frequency audiometry (HFA) up to 20 000 HZ. The results were compared with those obtained in a group of normally hearing persons with no history of noise exposure. Conserved high frequency hearing was found. Very strict selection criteria were applied in both groups in order to avoid hereditary diseases and to ensure normal middle ear function. The findings are in good overall agreement with histological findings in noise-exposed animals and also with high-frequency studies in the older literature. Two illustrative case stories from patients with severe 4--6 kHz dips are reported, one with preserved high-frequency hearing in spite of a considerable acoustic trauma and one with extreme sensitivity towards noise and with no hearing at all in the high frequencies. It is concluded that 1) HFA cannot be used as an early indicator of the traumatic effect of high intensity noise; 2) presbycusis and noise damage may be additive elements in the older age groups (above 50 years); 3) persons with abnormal high-frequency hearing are possibly hypersensitive towards excessive noise and HFA might be useful in the routine audiological evaluation of workers before these are exposed to noise.     

Psychometric evaluation of the Gothenburg Profile for measurement of experienced hearing disability and handicap: applications with new hearing aid candidates and experienced hearing aid users

The Gothenburg Profile (GP) for measurement of experienced hearing disability and handicap was developed with content partly taken from the shortened Hearing Measurement Scale (HMS25). The GP consists of 20 items divided into two subscales. The first subscale measures Experienced Disability as to hearing speech (items 1-5) and sound localization (items 6-10). The second subscale targets the Experienced Handicap in social settings (items 11-15) and the personal reactions to the experienced handicap (items 16-20). In this study, data are presented for new hearing aid candidates (NewHA) (n=441) and for experienced hearing aid users (ExpHA) (n=476). Principal components factor analyses were conducted and a three-factor solution was obtained, supporting the two factors of the Experienced Disability subscale, but just confirming one factor in the Experienced Handicap subscale. The internal consistency reliability (coefficient alpha) was good (0.85 to 0.95) for the subscales as was the test-retest reliability. The ExpHA group expressed significantly greater disability (first subscale) as well as experienced handicap (second subscale). However, when controlling for hearing level the differences disappeared. The clinical use of the GP for assessment of rehabilitation needs is recommended.     

Speech pattern audiometry in hearing impaired children

The aim of this study was to investigate the use of speech pattern audiometry (SPA) in assessing speech perception abilities of a group of 25 children with sensorineural hearing loss, and to compare their aided performance on SPA tests of four different phoneme contrasts with scores achieved on recorded Manchester Junior Word Lists (MJWL) at their most comfortable listening level (MCLL). The listeners were 25 children, 19 with congenital and six with acquired hearing loss aged between eight and 14 years. They were classified into three groups according to the severity of the hearing loss in the better hearing ear (20-60 dB HL, 61-80 dB HL and >81 dB HL).The SPA tests evaluated listeners' ability to identify word-initial plosives differing in the phonetic features of voicing and place of articulation. The main outcome measures were the SPA gradient measures, the SPA labelling function configuration and MJWL scores. The group with the most severe hearing loss (>81 dB HL) showed significantly poorer performance on the SPA tests and MJWL tests than the groups with mild (20-60 dB HL) to moderate (61-80 dB HL) hearing losses. There was significantly better performance on the two plosive voicing contrast tests than the two plosive place contrasts. For the MJWL, the performance of the group with the more severe hearing loss was also significantly different from the mild and moderate hearing loss groups. A MJWL score of up to 75% was associated with the random labelling configuration on all four SPA tests, emphasizing the different aspects of speech perception that were being examined with each type of test. This study suggests that there is a place for SPA as part of the test battery for speech perception testing in hearing-impaired children.     

Clinical evaluation of a new hearing aid anti-cardioid directivity pattern

Abstract

Objective: The purpose of this research was to evaluate a new directional hearing aid algorithm which automatically adapts to an anti-cardioid pattern in background noise when a speech signal originates from behind the hearing aid user. Design: Using the hearing-in-noise-test (HINT) in the soundfield, with the sentences delivered adaptively from the back (180°) and the standard HINT competing noise from the front (0°; 72 dB SPL), the participants were tested for three different hearing aid conditions: omnidirectional, conventional adaptive directional, and adaptive directional with the anti-cardioid algorithm enabled. Study Sample: Adults (n = 21) with bilaterally symmetrical downward sloping sensorineural hearing loss; experienced hearing aid users and aided bilaterally for experimental testing. Results: Results revealed a significant effect for the hearing aid microphone setting (p < .0001), with a HINT mean RTS of 4.2 dB for conventional adaptive directional, ?0.1 dB for omnidirectional, and ?5.7 dB when the anti-cardioid algorithm was active. This was a large effect size (Cohen's f2). Conclusion: The findings suggest that the signal classification system steered the algorithm correctly, and that when implemented, the anti-cardioid polar pattern resulted in an improvement in speech recognition in background noise for this listening situation.

Sumario

Objetivo: El propósito de esta investigación fue evaluar un nuevo algoritmo para auxiliares auditivos direccionales que se adapta automáticamente a un patrón anti-cardioide en ruido de fondo cuando una señal de lenguaje se origina detrás del usuario de un auxiliar auditivo. Diseño: Usando la prueba de audición-en-ruido (HINT), en campo libre, con oraciones enviadas adaptativamente desde atrás (180°) y el HINT estándar con ruido competitivo desde el frente (0°; 72 dB SPL), los participantes fueron evaluados en tres diferentes condiciones de escucha: omnidireccional, direccional adaptativa convencional y adaptativa direccional con el algoritmo anti-cardioide habilitado. Muestra de estudio: Adultos (n = 21) con pérdida auditiva bilateral simétrica, sensorineural, de perfil descendente, con experiencia en el uso de auxiliares auditivos y con adaptación bilateral para la prueba experimental. Resultados: Los resultados revelaron un efecto significativo para el ajuste del micrófono del auxiliar auditivo (p < .0001), con una HINT media y RTS de 4.2 dB para la forma direccional convencional adaptativa, ?0.1 dB para la omnidireccional y ?5.7 dB cuando se habilitóel algoritmo anti-cardioide. Este fue un efecto de gran envergadura (Cohen's f2). Conclusión: Los hallazgos sugieren que el sistema de clasificación de señales conducen el algorritmo correctamente y que cuando es habilitado, el patrón polar anti-cardioide determina una mejoría en el reconocimiento del lenguaje con ruido de fondo en esta situación de escucha.     

Paired-comparison hearing aid preferences: evaluation of an unforced-choice paradigm

Fifteen normal-hearing listeners compared nine frequency-response slopes in a round-robin paired-comparison tournament as they listened to passages of connected discourse against a competing noise background at a +3-dB signal-to-noise ratio. All participants listened in an AB paradigm, in which they were forced to choose which of two signals (A or B) produced better speech intelligibility, and an ABN paradigm, in which they were allowed a third choice of No Preference (N). For both paradigms, listeners generally preferred frequency shaping that either cut low frequencies or boosted high frequencies, and intra- and intersession reliability was high overall. Although listeners' most-preferred responses tended to converge on the same frequency-response slope in the two paradigms, the reliability of these responses was significantly higher for ABN than for AB. The use of the ABN paired-comparison paradigm deserves further study, therefore, as a method to fit multimemory hearing aids.