Maximum Real-Ear Gain of In-the-Ear Hearing Aids

1991 ◽  
Vol 34 (2) ◽  
pp. 351-359 ◽  
Author(s):  
Faye N. Erickson ◽  
Dianne J. Van Tasell
Keyword(s):  
Individual Differences ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Volume Control ◽  
Ear Canal ◽  
Shell Size ◽  
Maximum Gain ◽  
Functional Gain

Three hearing aid manufacturers provided custom full-shell in-the-ear hearing aids for each of 3 hearing-impaired subjects. Each manufacturer was instructed that the hearing aids should provide the maximum possible acoustic gain within the limits of hearing aid shell size and available components. Coupler gain, insertion gain, and functional gain were measured for each hearing aid. Gain measures were made with the volume control at either the full-on setting or the highest setting possible before the onset of acoustical feedback. Full-on coupler gain curves were similar across all nine hearing aids. Individual differences in concha/ear canal size and in the fit of the hearing aids produced substantial variance in insertion gain across hearing aids. Peak insertion gain varied from 41 to 58 dB. If 10 dB reserve gain is allowed, the range of estimated peak use gain from these maximum-gain in-the-ear hearing aids is 31–48 dB.

Frequency Responses of Hearing Aids and Their Effects on the Speech Perception of Hearing-Impaired Subjects

1975 ◽  
Vol 84 (5_suppl) ◽  
pp. 5-5 ◽  
Author(s):  
David Pedeo Pascoe
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
Word List ◽  
Hearing Impaired ◽  
Hearing Level ◽  
Closed Set ◽  
Frequency Responses ◽  
Significant Difference ◽  
Monosyllabic Words ◽  
Functional Gain

Eight hearing-impaired subjects were tested with a binaural master hearing aid. This aid has “on-the-head” miniature transducers and has an adjustable frequency response. Five frequency responses were used, two of them were defined by their response in a 2-cm3 coupler: 1) uniform coupler gain (UCG), and 2) 6 dB per octave rise (6 dB). The other responses were defined in terms of functional gain (difference between unaided and aided thresholds): 3) uniform functional gain (UFG); 4) uniform hearing level (UHL); and 5) a simulation of a commercial hearing aid (AS). A significant difference between coupler and functional gain was seen. Discrimination was tested with a special closed-set word list which includes fifty monosyllabic words with a high percentage of voiceless phonemes. Discrimination scores were consistently better with the UHL response. The lowest scores were obtained with the AS response. The average difference in scores between these two responses was 18.4%. Further testing replicated these results and also compared the effects of a different type of word list phonetically balanced (PB); with these lists, the above-mentioned difference in scores was smaller in quiet (5.9%) but larger in noise (20.9%).

scholarly journals Nonlinear Hearing Aids and Verification of Fitting Targets

2003 ◽  
Vol 7 (3) ◽  
pp. 99-115 ◽  
Author(s):  
David A. Fabry
Keyword(s):  
Noise Reduction ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Advantages And Disadvantages ◽  
Evaluation Protocol ◽  
Measurement Strategies ◽  
Functional Gain ◽  
Urban Legend

This paper addresses the issue of initial verification of hearing aid gain and output for nonlinear hearing aids. Specifically, “urban legend” has it that nonlinear hearing aids with digital noise reduction circuitry may not be accurately measured using functional gain and/or probe microphone measures. Discussed are the advantages and disadvantages of both measurement strategies, and how they may be used to “acoustically match” hearing aids to individual patients. An evaluation protocol that employs both optimal aided thresholds and probe microphone measurements to assess gain, output, and audibility in hearing-impaired patients.

Comparison of Hearing-Aid Gain Using Functional, Coupler, and Probe-Tube Measurements

1986 ◽  
Vol 29 (2) ◽  
pp. 218-226 ◽  
Author(s):  
David Mason ◽  
Gerald R. Popelka
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
Sound Field ◽  
Average Difference ◽  
Ear Canal ◽  
Tube System ◽  
Acoustic Characteristics ◽  
Standard Deviations ◽  
Functional Gain

Measurements of functional gain were compared first to coupler gain for 57 subjects using one of three hearing aid—earmold combinations and second to probe-tube gain for 12 subjects using in-the-ear hearing aids. The average difference between functional and coupler gain plotted as a function of frequency yielded results that were similar to previous reports, with the greatest effects occurring at 3000 and 4000 Hz. Significant differences were seen among hearing aid—earmold combinations at 3000, 4000, and 6000 Hz. Standard deviations for measurements between 750 and 2000 Hz were less than 5 dB and could be explained by variability of functional gain measures associated with test—retest variability of thresholds measured in a sound field. Below 750 Hz and above 2000 Hz, standard deviations exceeded 5 dB. The greater variability may be explained by differences in earmold venting, acoustic characteristics of the ear canal, and stimuli used to measure functional and coupler gain. Neither room nor hearing-aid noise appeared to affect the results significantly. When functional gain was compared to insertion gain measured with a probe-tube system, the average difference across frequencies was less than 1 dB. The variability of the differences at all frequencies, with the exception of 6000 Hz, was within the range reported for functional gain measurements. It was concluded that functional gain can be accurately estimated using probe-tube measurements.

Frequency Responses of Hearing Aids and Their Effects on the Speech Perception of Hearing-Impaired Subjects

1975 ◽  
Vol 84 (23_suppl) ◽  
pp. 3-40 ◽  
Author(s):  
David Pedro Pascoe
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
Word List ◽  
Hearing Impaired ◽  
Hearing Level ◽  
Closed Set ◽  
Frequency Responses ◽  
Significant Difference ◽  
Monosyllabic Words ◽  
Functional Gain

Eight hearing-impaired subjects were tested with a binaural master hearing aid. This aid has “on-the-head” miniature transducers and has an adjustable frequency response. Five frequency responses were used, two of them were defined by their response in a 2-cm3 coupler: 1) uniform coupler gain (UCG), and 2) 6 dB per octave rise (6 dB). The other responses were defined in terms of functional gain (difference between unaided and aided thresholds): 3) uniform functional gain (UFG); 4) uniform hearing level (UHL); and 5) a simulation of a commercial hearing aid (AS). A significant difference between coupler and functional gain was seen. Discrimination was tested with a special closed-set word list which includes fifty monosyllabic words with a high percentage of voiceless phonemes. Discrimination scores were consistently better with the UHL response. The lowest scores were obtained with the AS response. The average difference in scores between these two responses was 18.4%. Further testing replicated these results and also compared the effects of a different type of word list phonetically balanced (PB); with these lists, die above-mentioned difference in scores was smaller in quiet (5.9%) but larger in noise (20.9%).

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

scholarly journals Survey of Hearing Aid Conditions for Hearing Impaired Persons While Driving

2020 ◽  
pp. 132-136
Author(s):  
Hiroshi Ikeda ◽  
Shigeyuki Minami
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Visual Information ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Safe Driving ◽  
Actual Usage ◽  
Hearing Ability ◽  
Acquired Hearing Loss ◽  
The Impact

Hearing impaired persons are required to drive with hearing aids to supplement their hearing ability, however, there has not been sufficient discussion regarding the impact of the use of a hearing aid on driving a vehicle. In order to investigate the actual usage and driving conditions of using hearing aids while driving a vehicle, this paper uses a questionnaire to survey (1) how easy it is to drive when wearing hearing aids, and (2) how often hearing aids are not worn while driving. Concerning the ease of driving when wearing a hearing aid, it was suggested that people with congenital hearing loss were more likely to rely on visual information, and those with acquired hearing loss continue to use their experience of hearing. When the level of disability is high, it is difficult to drive when using the hearing aid, and when the disability level is low, it is easier to drive. Regarding the frequency of driving without wearing hearing aids, about 60 % of respondents had such an experience. Those who often drive without hearing aids had experienced headaches due to noise from wearing hearing aids compared to those who wear hearing aids at all times. Hearing aids are necessary assistive devices for hearing impaired persons to obtain hearing information, and to provide a safe driving environment. Therefore, this paper addresses issues to maintain a comfortable driving environment while wearing a hearing aid.

Evaluation of an Articulation-Index Based Model for Predicting the Effects of Adaptive Frequency Response Hearing Aids

1990 ◽  
Vol 33 (4) ◽  
pp. 676-689 ◽  
Author(s):  
David A. Fabry ◽  
Dianne J. Van Tasell
Keyword(s):  
Transfer Function ◽  
Frequency Response ◽  
Hearing Aids ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Articulation Index ◽  
Intelligibility Ratings ◽  
High Pass

The Articulation Index (AI) was used to evaluate an “adaptive frequency response” (AFR) hearing aid with amplification characteristics that automatically change to become more high-pass with increasing levels of background noise. Speech intelligibility ratings of connected discourse by normal-hearing subjects were predicted well by an empirically derived AI transfer function. That transfer function was used to predict aided speech intelligibility ratings by 12 hearing-impaired subjects wearing a master hearing aid with the Argosy Manhattan Circuit enabled (AFR-on) or disabled (AFR-off). For all subjects, the AI predicted no improvements in speech intelligibility for the AFR-on versus AFR-off condition, and no significant improvements in rated intelligibility were observed. The ability of the AI to predict aided speech intelligibility varied across subjects. However, ratings from every hearing-impaired subject were related monotonically to AI. Therefore, AI calculations may be used to predict relative—but not absolute—levels of speech intelligibility produced under different amplification conditions.

Decreased Use of Hearing Aids following Training in Hearing Tactics

1998 ◽  
Vol 87 (2) ◽  
pp. 703-706 ◽  
Author(s):  
Gerhard Andersson
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Daily Average ◽  
Randomized Controlled ◽  
Hearing Aid Use ◽  
Randomized Controlled Studies ◽  
Report Data

In this report data on hearing aid use were combined from three randomized controlled studies on behavioural hearing tactics. Daily average hearing aid use at pretreatment and posttreatment were analysed for 63 older hearing-impaired persons who had either received treatment or acted as controls. Analysis showed a significant, albeit weak, decrease in daily hearing aid use for those subjects who had received the treatment. The utility of amount of hearing aid use as an indicator of rehabilitation success is discussed.

Relationship of Acoustic Gain to Aided Threshold Improvement in Children

1978 ◽  
Vol 43 (3) ◽  
pp. 348-352 ◽  
Author(s):  
Robert E. Jirsa ◽  
Thomas W. Norris
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Variable Volume ◽  
Relationship Of ◽  
Impaired Children ◽  
Hearing Impaired Children

Aided threshold improvement obtained by 12 hearing-impaired children was compared to the acoustic gain of their hearing aids using both the traditional 2-cc coupler and a variable volume coupler designed to approximate real ear volume in children. Results indicated that acoustic gain determined in the 2-cc coupler underestimated aided threshold improvement by approximately 8.7 dB. Use of the variable volume coupler to determine acoustic gain, however, adequately predicted aided improvement at comfort setting. Use of the variable volume coupler in hearing-aid fittings for children is discussed with special emphasis on preventing over-amplification.

Predicted Gain and Functional Gain With Transcranial Routing of Signal Completely-in-the-Canal Hearing Aids

2003 ◽  
Vol 12 (2) ◽  
pp. 84-90 ◽  
Author(s):  
Marc A. Fagelson ◽  
Colleen M. Noe ◽  
Owen D. Murnane ◽  
Jennifer S. Blevins
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Mechanical Vibration ◽  
Signal Frequency ◽  
Unilateral Hearing Loss ◽  
External Canal ◽  
The Difference ◽  
Acoustic Output ◽  
Functional Gain

Transcranial routing of signal (TCROS) was accomplished using completely-in-the-canal (CIC) hearing aids in 5 profoundly unilaterally hearing-impaired individuals. The functional gain realized by the participants far exceeded the gain predicted by measuring the acoustic output and real ear aided response of the hearing aids. The difference between predicted and functional gain increased with signal frequency and was attributed at least in part to mechanical vibration of the hearing aid in the external canal. Implications for fitting unilateral hearing loss using TCROS amplifying systems are discussed.

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