The time course and magnitude of perceptual acclimatization to frequency responses: Evidence from monaural fitting of hearing aids

1992 ◽  
Vol 92 (3) ◽  
pp. 1258-1268 ◽  
Author(s):  
Stuart Gatehouse
Keyword(s):  
Hearing Aids ◽  
Time Course ◽  
Frequency Responses

The efficacy of the Prescription of Gain/Output (POGO) in fitting hearing aids to mild and moderate sensorineural hearing losses

1994 ◽  
Vol 41 (1) ◽  
Author(s):  
Sandra Thorpe ◽  
Carol Jardine
Keyword(s):  
Word Recognition ◽  
Hearing Aids ◽  
User Satisfaction ◽  
Sensorineural Hearing ◽  
Subjective Ratings ◽  
Frequency Responses ◽  
Perceived Benefit ◽  
Functional Gain ◽  
Modified Functional ◽  
Fitting Hearing Aids

This study investigated the effectiveness of the application of the Prescription of Gain/Output (POGO) in hearing aid fittings. Six subjects were tested. Each presented with binaural mild to moderate sensorineural hearing losses and were previously fitted monaurally with behind-the-ear aids using modifications of the traditional Carhart (1946) approach. Functional gain requirements stipulated by POGO were calculated from unaided thresholds and compared to actual functional gain measurements. Five subjects, whose functional gain measures were not within prescribed limits, were referred for modification of the gain and frequency responses of their hearing aids and earmoulds. Post-modified functional gain measurements were analysed. The extent to which the required functional gain measurements were met, was investigated statistically in relation to word recognition scores and subjective ratings of perceived benefit. The conclusion reached was that the application of POGO results in improved word recognition scores and self-reported user satisfaction.

Evaluation of Hardwire Personal Assistive Listening Devices

1994 ◽  
Vol 3 (2) ◽  
pp. 71-77 ◽  
Author(s):  
James J. Dempsey ◽  
Mark Ross
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Low Frequency ◽  
Sensorineural Hearing ◽  
Clinical Implications ◽  
Frequency Responses ◽  
Subjective Evaluations ◽  
Potential Benefits

A large number of personal amplifiers have recently become available commercially. These devices have not been classified as hearing aids by the FDA and are therefore not subject to the FDA rules and regulations governing the sales of hearing aid devices. In this investigation, several of these personal amplifiers were evaluated to determine potential benefits and problems for each device. The devices were evaluated electroacoustically and, also, subjectively by a group of adults with sensorineural hearing loss. The results of the electroacoustic evaluation revealed very sharply peaked frequency responses. The subjective evaluations revealed tremendous variability, with some preferences for power and low-frequency amplification. Clinical implications of these results and suggestions for further research are provided.

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%).

Role of Infant Vocal Development in Candidacy for and Efficacy of Cochlear Implantation

2002 ◽  
Vol 111 (5_suppl) ◽  
pp. 52-55 ◽  
Author(s):  
Jan Allison Moore ◽  
Sandie Bass-Ringdahl
Keyword(s):  
Hearing Aids ◽  
Motor Development ◽  
Cochlear Implantation ◽  
Time Course ◽  
Time Frame ◽  
Sufficient Evidence ◽  
Vocal Development ◽  
Profound Hearing Loss ◽  
Auditory Experience ◽  
Canonical Babbling

Previous research has documented the importance of audition in the development of typical infant vocalization. Of particular interest is the development of canonical babbling, which is related to mastery of the timing elements of speech. Children with severe to profound hearing loss who use hearing aids have demonstrated both delayed and deviant canonical babbling. The vocal development of 12 children has been followed as they have been considered for cochlear implantation. Nine of these children have undergone implantation, and 5 of these children have been followed for more than 1 year after implantation. On average, canonical babbling emerged at 6.5 months after implantation. The time frame in which some children developed words was accelerated in terms of length of auditory experience as compared with normal-hearing peers. Mature oral-motor development is likely the primary contributing factor in this time course. One child who received a cochlear implant began to babble with hearing aids. It is not known whether normal canonical babbling is sufficient evidence on which to base candidacy decisions; however, our data suggest that children who produce canonical babbling maintain and build upon those skills after implantation.

Loudness Matching of Signals Spectrally Shaped by a Simulated Hearing Aid

1993 ◽  
Vol 36 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Jerry Punch ◽  
Brad Rakerd
Keyword(s):  
Hearing Aids ◽  
Hearing Aid ◽  
General Pattern ◽  
Preliminary Evidence ◽  
Multiple Frequency ◽  
Frequency Range ◽  
Frequency Responses ◽  
The Individual ◽  
Spectral Tilt

A hearing aid with multiple frequency responses was simulated by programming an equalizer to produce spectral tilt factors of -6, 0, and +6 dB/octave over the frequency range from 0.25 kHz to 4 kHz. Listeners with normal hearing matched the loudness of signals (speech and white noise) that were shaped by these different equalizer settings and delivered via an insert earphone. All signals with spectra that were tilted, either negatively or positively, were perceived as louder than untilted signals. The general pattern of loudness matching was similar across subjects, and intrasubject judgments were found to be highly transitive. A measure of signal power was found to account only moderately well for the individual data. Preliminary evidence from a follow-up study using tilt factors less severe than those used in the main experiment suggests that loudness differences are roughly proportional to the degree of spectral tilt. The incorporation of level corrections approximating those necessary to achieve equal loudness is recommended in the fitting of programmable hearing aids.

scholarly journals Tracking of Noise Tolerance to Measure Hearing Aid Benefit

2017 ◽  
Vol 28 (08) ◽  
pp. 698-707
Author(s):  
Francis Kuk ◽  
Eric Seper ◽  
Chi-Chuen Lau ◽  
Petri Korhonen
Keyword(s):  
Hearing Aids ◽  
Noise Level ◽  
Time Course ◽  
Hearing Aid ◽  
Stable State ◽  
Normal Hearing ◽  
Noise Tolerance ◽  
Repeated Measures Design ◽  
Directional Microphone ◽  
Test Conditions

AbstractThe benefits offered by noise reduction (NR) features on a hearing aid had been studied traditionally using test conditions that set the hearing aids into a stable state of performance. While adequate, this approach does not allow the differentiation of two NR algorithms that differ in their timing characteristics (i.e., activation and stabilization time).The current study investigated a new method of measuring noise tolerance (Tracking of Noise Tolerance [TNT]) as a means to differentiate hearing aid technologies. The study determined the within-session and between-session reliability of the procedure. The benefits provided by various hearing aid conditions (aided, two NR algorithms, and a directional microphone algorithm) were measured using this procedure. Performance on normal-hearing listeners was also measured for referencing.A single-blinded, repeated-measures design was used.Thirteen experienced hearing aid wearers with a bilaterally symmetrical (≤10 dB) mild-to-moderate sensorineural hearing loss participated in the study. In addition, seven normal-hearing listeners were tested in the unaided condition.Participants tracked the noise level that met the criterion of tolerable noise level (TNL) in the presence of an 85 dB SPL continuous discourse passage. The test conditions included an unaided condition and an aided condition with combinations of NR and microphone modes within the UNIQUE hearing aid (omnidirectional microphone, no NR; omnidirectional microphone, NR; directional microphone, no NR; and directional microphone, NR) and the DREAM hearing aid (omnidirectional microphone, no NR; omnidirectional microphone, NR). Each tracking trial lasted 2 min for each hearing aid condition. Normal-hearing listeners tracked in the unaided condition only. Nine of the 13 hearing-impaired listeners returned after 3 mo for retesting in the unaided and aided conditions with the UNIQUE hearing aid. The individual TNL was estimated for each participant for all test conditions. The TNT index was calculated as the difference between 85 dB SPL and the TNL.The TNT index varied from 2.2 dB in the omnidirectional microphone, no NR condition to −4.4 dB in the directional microphone, NR on condition. Normal-hearing listeners reported a TNT index of −5.7 dB using this procedure. The averaged improvement in TNT offered by the NR algorithm on the UNIQUE varied from 2.1 dB when used with a directional microphone to 3.0 dB when used with the omnidirectional microphone. The time course of the NR algorithm was different between the UNIQUE and the DREAM hearing aids, with the UNIQUE reaching a stable TNL sooner than the DREAM. The averaged improvement in TNT index from the UNIQUE directional microphone was 3.6 dB when NR was activated and 4.4 dB when NR was deactivated. Together, directional microphone and NR resulted in a total TNT improvement of 6.5 dB. The test–retest reliability of the procedure was high, with an intrasession 95% confidence interval (CI) of 2.2 dB and an intersession 95% CI of 4.2 dB.The effect of the NR and directional microphone algorithms was measured to be 2–3 and 3.6–4.4 dB, respectively, using the TNT procedure. Because of its tracking property and reliability, this procedure may hold promise in differentiating among some hearing aid features that also differ in their time course of action.

Permanent Threshold Shift Associated With Overamplification by Hearing Aids

1991 ◽  
Vol 34 (2) ◽  
pp. 403-414 ◽  
Author(s):  
John H. Macrae
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Hearing Aids ◽  
Time Course ◽  
Noise Exposure ◽  
High Volume ◽  
Normal Hearing ◽  
Sensorineural Hearing ◽  
Threshold Shift ◽  
Volume Control

Humes and Jesteadt have proposed that the Modified Power Law (MPL) provides a means of predicting permanent threshold shift (PTS) due to noise exposure in subjects with preexisting sensorineural hearing loss. Data concerning PTS attributed to overamplification by hearing aids in 8 children with severe sensorineural hearing loss were used to evaluate the MPL hypothesis. The excessive amplification was partly due to use by the children of very high volume-control settings instead of mid-range volume-control settings. The PTS tended to be flat across frequency. Its course in time was a miniature version of the time course of PTS that would be induced by a similar noise exposure in a person with normal hearing. It began to occur soon after the start of hearing aid use and its rate of development was slower than that which would occur in a person with normal hearing. The growth of PTS could be predicted from the estimated real ear output levels of the children’s hearing aids by means of the MPL combined with the logarithmic equation proposed by Kraak for predicting the effect of noise exposure on hearing.

Input Stimuli for Obtaining Frequency Responses of Automatic Gain Control Hearing Aids

1989 ◽  
Vol 32 (1) ◽  
pp. 189-194 ◽  
Author(s):  
David A. Preves ◽  
Lucille B. Beck ◽  
Edwin D. Burnett ◽  
Harry Teder
Keyword(s):  
Frequency Response ◽  
Hearing Aids ◽  
Input Signal ◽  
Pure Tone ◽  
Automatic Gain Control ◽  
Broad Band ◽  
Gain Control ◽  
Response Curves ◽  
Frequency Responses ◽  
Band Noise

Developing a family of frequency response curves for AGC types of hearing instruments using swept pure tones at varying input levels often produces erroneous results. This problem is caused by exceeding the threshold for activating the AGC circuit at some frequencies but not at other frequencies during the pure-tone sweep, thereby producing a different frequency response from that which would be obtained with a complex input signal such as speech-shaped noise. This measurement artifact may be minimized by ensuring that the threshold for activating the AGC circuit is either always exceeded or never exceeded during the development of a frequency response curve. Three input signals are compared for developing a family of frequency responses for an AGC hearing aid: (1) swept pure tone, (2) swept pure tone with bias tone added, and (3) shaped broad-band noise. The shaped broad-band noise appears to be the input signal of choice.

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