A Comparison of the Aided Performance and Benefit Provided by a Linear and a Two-Channel Wide Dynamic Range Compression Hearing Aid

1999 ◽  
Vol 42 (1) ◽  
pp. 65-79 ◽  
Author(s):  
Larry E. Humes ◽  
Laurel Christensen ◽  
Tara Thomas ◽  
Fred H. Bess ◽  
Andrea Hedley-Williams ◽  
...  
Keyword(s):  
Outcome Measures ◽  
Hearing Aids ◽  
Dynamic Range ◽  
Hearing Aid ◽  
Self Report ◽  
Volume Control ◽  
Listening Effort ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
Monosyllabic Words

The aided performance and benefit achieved with linear and two-channel wide dynamic range compression (WDRC) in-the-canal (ITC) hearing aids were established in 55 individuals. Study participants had been wearing either linear or adaptive-frequency-response (Bass Increase at Low Levels, BILL) ITC hearing aids for approximately one year before participation in this study. Outcome measures included aided performance and objective benefit in quiet and noise at a variety of speech levels (50, 60, and 75 dB SPL), at various levels of babble background (quiet, signal-to-babble ratios of +5 and +10 dB), and for various types of test materials (monosyllabic words and sentences in connected speech). Several subjective measures of aided performance (sound-quality judgments and magnitude estimates of listening effort) and relative benefit (improvement in listening effort and the Hearing Aid Performance Inventory, HAPI) were also obtained. Finally, self-report measures of hearing-aid use were also obtained using daily logs. Participants completed all outcome measures for the linear ITC hearing aids first, following 2 months of usage, and then repeated all outcome measures for the WDRC instruments after a subsequent 2-month period of use. In general, although both types of hearing aids demonstrated significant benefit, the results indicated that the WDRC instruments were superior to the linear devices for many of the outcome measures. This tended to be the case most frequently when low speech levels were used. Many of the performance differences between devices most likely can be ascribed to differences in gain, and prescriptive approaches (DSL[i/o] vs. NAL-R), for the fixed volume control testing performed in this study.

scholarly journals Modeling and Predicting Hearing Aid Outcome

2003 ◽  
Vol 7 (2) ◽  
pp. 41-75 ◽  
Author(s):  
Larry E. Humes
Keyword(s):  
Factor Analysis ◽  
Individual Differences ◽  
Outcome Measures ◽  
Hearing Aids ◽  
Dynamic Range ◽  
Single Channel ◽  
Hearing Aid ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
Hearing Aid Use

Following a brief tutorial on the application of factor analysis to hearing aid outcome measures, three studies of hearing aid outcome measures in elderly adults are presented and analyzed. Two of the studies were completed at Indiana University (IU-1 and IU-2), and one was a collaborative multisite study by the Veterans Administration and the National Institute of Deafness and other Communication Disorders (NIDCD/VA). IU-1 measured hearing aid outcome in 173 elderly wearers of single-channel, linear, in-the-ear hearing aids with output-limiting compression, whereas IU-2 obtained the same extensive set of outcome measures from 53 elderly wearers of two-channel, wide-dynamic-range compression, in-the-canal hearing aids. In the NIDCD/VA study, 333 to 338 participants wore three single-channel circuits in succession, with each circuit housed within an in-the-ear shell. The three circuits included in that study and in this analysis were: (1) linear with peak clipping, (2) linear with output-limiting compression, and (3) single-channel, wide-dynamic-range compression. Evaluation of the many outcome measures completed in each study using principal components factor analysis revealed that from three (both IU studies) to five (NIDCD/VA study) principal components captured the individual differences in hearing aid outcome. This was independent of hearing aid type (in-the-ear or in-the-canal) and circuitry. Subsequent multiple regression analyses of individual differences in performance along each dimension of hearing aid outcome revealed that these individual differences could be accounted for reasonably well by various prefit variables for some dimensions of outcome, but not others. In general, measures of speech recognition performance were well accounted for by prefit measures, with the best predictors being hearing loss, cognitive performance, and age. Measures of hearing aid usage were less well accounted for by prefit measures, with the most accurate predictor of current hearing aid use being prior hearing aid use. The outcome dimension accounted for most poorly was that associated with hearing aid satisfaction, with subjective measures of aided sound quality being the best predictor of performance along this dimension of hearing aid outcome. Additional multicenter, large-scale studies are needed to develop more complete models of hearing aid outcome and to identify the variables that influence various aspects of hearing aid outcome. It is only through this additional research that it will be possible to optimize outcome for hearing aid wearers.

Comparison of Multichannel Wide Dynamic Range Compression and ChannelFree Processing Strategies on Consonant Recognition

2015 ◽  
Vol 26 (07) ◽  
pp. 607-614 ◽  
Author(s):  
Patrick Plyler ◽  
Mark Hedrick ◽  
Brittany Rinehart ◽  
Rebekah Tripp
Keyword(s):  
Hearing Aids ◽  
Repeated Measures ◽  
Dynamic Range ◽  
Hearing Aid ◽  
Previous Experience ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
Processing Strategies ◽  
Hearing Aid Use ◽  
Subjective Preference

Background: Both wide dynamic range compression (WDRC) and ChannelFree (CF) processing strategies in hearing aids were designed to improve listener comfort and consonant identification, yet few studies have actually compared them. Purpose: To determine whether CF processing provides equal or better consonant identification and subjective preference than WDRC. Research Design: A repeated-measures randomized design was used in which each participant identified consonants from prerecorded nonsense vowel–consonant–vowel syllables in three conditions: unaided, aided using CF processing, and aided using WDRC processing. For each of the three conditions, syllables were presented in quiet and in a speech-noise background. Participants were also asked to rate the two processing schemes according to overall preference, preference in quiet and noise, and sound quality. Study Sample: Twenty adults (seven females; mean age 69.7 yr) with ≥1 yr of hearing aid use participated. Ten participants had previous experience wearing aids with WDRC, and 10 had previous experience with CF processing. Participants were tested with both WDRC and CF processing. Data Collection and Analysis: Number of consonants correct were measured and used as the dependent variable in analyses of variance with subsequent post hoc testing. For subjective preference, a listener rating form was employed with subsequent χ2 analysis. Results: Overall results showed that signal-processing strategy did not significantly affect consonant identification or subjective preference, nor did previous hearing aid use influence results. Listeners with audiometric slopes exceeding 11 dB per octave, however, preferred CF processing and performed better in noise with CF processing. Conclusion: CF processing is a viable alternative to WDRC for listeners with more severely sloping audiometric contours.

Loudness and Satisfaction Ratings for Hearing Aid Users

2009 ◽  
Vol 20 (04) ◽  
pp. 272-282 ◽  
Author(s):  
Peter J. Blamey ◽  
Lois F.A. Martin
Keyword(s):  
Hearing Aids ◽  
Dynamic Range ◽  
Hearing Aid ◽  
Strong Relationship ◽  
Impaired Hearing ◽  
Soft Or ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
Hearing Thresholds ◽  
Comfortable Loudness

Background: Hearing aids amplify low-intensity sounds to make them audible while keeping high-intensity sounds at an acceptable loudness for listeners with impaired hearing. Purpose: The purpose of this analysis was to assess loudness and satisfaction at the same time using a combined loudness and satisfaction questionnaire to rate 18 everyday environmental sounds. Research Design: Ten sets of data from four studies, covering three conditions, were analyzed. The three conditions were unaided, wide dynamic range compression (WDRC), and adaptive dynamic range optimization (ADRO®). In total, there were 61 subjects giving over 3,000 pairs of ratings for loudness and satisfaction. Results: The analysis found a strong relationship between loudness and satisfaction ratings for this set of listeners and conditions. The maximum satisfaction ratings corresponded to sounds with “comfortable” loudness ratings. Satisfaction was lowest for sounds that were “uncomfortably loud.” Sounds that were very soft or inaudible also received low satisfaction ratings unless the sounds were expected to be soft, such as the sound of one's own breathing. Conclusions: Hearing aid fittings that place most sounds at a comfortable level are likely to be more satisfactory than hearing aid fittings that produce more sounds close to hearing thresholds or discomfort levels. Aided conditions gave higher loudness and satisfaction ratings than the unaided condition, and the ADRO hearing aids gave significantly higher satisfaction ratings than the WDRC hearing aids.

Effect of a Single-Channel Wide Dynamic Range Compression Circuit on Perception of Stop Consonant Place of Articulation

2000 ◽  
Vol 43 (5) ◽  
pp. 1174-1184 ◽  
Author(s):  
Mark S. Hedrick ◽  
Tracie Rice
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Dynamic Range ◽  
Single Channel ◽  
Hearing Aid ◽  
Category Boundary ◽  
Frequency Region ◽  
Wide Dynamic Range ◽  
Place Of Articulation ◽  
Dynamic Range Compression

Previous studies have shown that altering the amplitude of a consonant in a specific frequency region relative to an adjacent vowel's amplitude in the same frequency region will affect listeners' perception of the consonant place of articulation. Hearing aids with single-channel, fast-acting wide dynamic range compression (WDRC) alter the overall consonant-vowel (CV) intensity ratio by increasing consonant energy. Perhaps one reason WDRC has had limited success in improving speech recognition performance is that the natural amplitude balances between consonant and vowel are altered in crucial frequency regions, thus disturbing the aforementioned amplitude cue for determining place of articulation. The current study investigated the effect of a WDRC circuit on listeners' perception of place of articulation when the relative amplitude of consonant and vowel was manipulated. The stimuli were a continuum of synthetic CV syllables stripped of all place cues except relative consonant amplitudes. Acoustic analysis of the CVs before and after hearing aid processing showed a predictable increase in high-frequency energy, particularly for the burst of the consonant. Alveolar bursts had more high-frequency energy than labial bursts. Twenty-five listeners with normal hearing and 5 listeners with sensorineural hearing loss labeled the consonant sound of the CV syllables in unaided form and after the syllables were recorded through a hearing aid with single-channel WDRC. There were significantly more listeners who were unable to produce a category boundary when labeling the aided stimuli. Of those listeners who did yield a category boundary for both aided and unaided stimuli, there were significantly more alveolar responses for the aided condition. These results can be explained by the acoustic analyses of the aided stimuli.

Speech and Music Quality Ratings for Linear and Nonlinear Hearing Aid Circuitry

2007 ◽  
Vol 18 (08) ◽  
pp. 688-699 ◽  
Author(s):  
Evelyn Davies-Venn ◽  
Pamela Souza ◽  
David Fabry
Keyword(s):  
Hearing Aids ◽  
Dynamic Range ◽  
Hearing Aid ◽  
Significant Preference ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
Quality Ratings ◽  
Linear And Nonlinear ◽  
Moderate Hearing Loss

This study evaluated quality ratings for speech and music stimuli processed using peak clipping (PC), compression limiting (CL), and wide-dynamic range compression (WDRC) hearing aid circuitry. Eighteen listeners with mild-to-moderate hearing loss were binaurally fitted with behind-the-ear (BTE) hearing aids and instructed to rate the quality of speech under various conditions in quiet and noise and two genres of music. Results for speech revealed a slight preference for WDRC at 80 dB SPL, and equivalent ratings for the three circuits under all other listening conditions. Music ratings revealed a marginally significant preference for WDRC and a preference for classical over popular music. For music, judgments on pleasantness were the most influential on overall circuit preference. Este estudio evalúa estimaciones de calidad para estímulos de lenguaje y música procesados usando corte de picos (PC), limitación de la compresión (CL) y compresión de rango dinámico amplio (WDRC) en los circuitos del auxiliar auditivo. Dieciocho sujetos con hipoacusia leve a moderada fueron adaptados binauralmente con auxiliares auditivos retroauriculares (BTE) e instruidos para juzgar la calidad del lenguaje bajo varias condiciones de silencio y ruido, y la de dos géneros de música. Los resultados para el lenguaje revelaron una ligera preferencia para el WDRC a 80 dB SPL, y estimaciones equivalentes para los tres circuitos en las otras condiciones de escucha. Las estimaciones para la música revelaron una preferencia marginalmente significativa para el WDRC y una preferencia para la música clásica por encima de la popular. Para la música, los juicios de agradabilidad fueron los que más influyeron en la preferencia global de los circuitos.

A 1-Channel 3-Band Wide Dynamic Range Compression Chip for Vibration Transducer of Implantable Hearing Aids

2014 ◽  
Vol 24 (1) ◽  
pp. 1009-1017 ◽  
Author(s):  
DongWook Kim ◽  
KiWoong Seong ◽  
MyoungNam Kim ◽  
JinHo Cho ◽  
JyungHyun Lee
Keyword(s):  
Hearing Aids ◽  
Dynamic Range ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
Vibration Transducer ◽  
Implantable Hearing Aids

Hearing-Aid Outcome Measures Following One Month of Hearing Aid Use by the Elderly

2001 ◽  
Vol 44 (3) ◽  
pp. 469-486 ◽  
Author(s):  
Larry E. Humes ◽  
Carolyn B. Garner ◽  
Dana L. Wilson ◽  
Nancy N. Barlow
Keyword(s):  
Factor Analysis ◽  
Outcome Measures ◽  
Hearing Aids ◽  
Hearing Aid ◽  
The Elderly ◽  
Self Report ◽  
Elderly Persons ◽  
Impaired Hearing ◽  
Hearing Aid Use ◽  
Class D

This study reports the results of a large number of hearing-aid outcome measures obtained from 173 elderly hearing-aid wearers following one month of hearing-aid use. All participants in this study were fit binaurally with identical full-concha in-the-ear (ITE) hearing aids having linear Class-D amplifiers with output-limiting compression. Outcome measures included several measures of speech recognition, as well as several self-report measures of hearing-aid performance, benefit, satisfaction, and use. Comparison of mean data from this sample of hearing-aid wearers to other larger sets of data, obtained previously for several of these measures of hearing-aid outcome evaluated in isolation, indicated that the participants in this study were representative of the participants in other largerscale studies. Subsequent principal-components factor analysis of the data from this study indicated that there were seven distinct dimensions of hearing-aid outcome. Attempts to document the effectiveness and efficacy of hearing aids for elderly persons with impaired hearing will be most complete when assessing performance along all seven dimensions of hearing-aid outcome. Clinically efficient procedures for doing so are discussed.

An Optimized Design Strategy for the Hardware Implementation of the Hearing Aid Algorithms

2015 ◽  
Vol 719-720 ◽  
pp. 548-553
Author(s):  
Feng Guo ◽  
Shan Shan Yong ◽  
Zhao Yang Guo ◽  
Xin An Wang ◽  
Guo Xin Zhang
Keyword(s):  
Hardware Implementation ◽  
Dynamic Range ◽  
Automatic Gain Control ◽  
Hearing Aid ◽  
Gain Control ◽  
Design Strategy ◽  
Optimized Design ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression ◽  
The Common

In this paper, a new design strategy for the hardware implementation of hearing aid algorithms is proposed. Two familiar hearing aid algorithms—Wide Dynamic Range Compression (WDRC) and Automatic Gain Control (AGC)—are implemented in one circuit as an example. By putting the common arithmetic procedures into common module, the operation units can be used repeatedly. In this way, the area and power consumption are visibly reduced.

Fitting Wide Dynamic Range Compression Hearing Aids

1997 ◽  
Vol 6 (3) ◽  
pp. 19-28 ◽  
Author(s):  
George A. Lindley ◽  
Catherine V. Palmer
Keyword(s):  
Hearing Aids ◽  
Dynamic Range ◽  
Wide Dynamic Range ◽  
Dynamic Range Compression
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