Effects of Linear Amplification and Amplitude Compression on Sentence Reception by Listeners With Hearing Loss Simulated by Masking Noise

2019 ◽  
pp. 131-147
Author(s):  
Steven V. De Gennaro ◽  
Louis D. Braida
2019 ◽  
Vol 23 ◽  
pp. 233121651988761 ◽  
Author(s):  
Gilles Courtois ◽  
Vincent Grimaldi ◽  
Hervé Lissek ◽  
Philippe Estoppey ◽  
Eleftheria Georganti

The auditory system allows the estimation of the distance to sound-emitting objects using multiple spatial cues. In virtual acoustics over headphones, a prerequisite to render auditory distance impression is sound externalization, which denotes the perception of synthesized stimuli outside of the head. Prior studies have found that listeners with mild-to-moderate hearing loss are able to perceive auditory distance and are sensitive to externalization. However, this ability may be degraded by certain factors, such as non-linear amplification in hearing aids or the use of a remote wireless microphone. In this study, 10 normal-hearing and 20 moderate-to-profound hearing-impaired listeners were instructed to estimate the distance of stimuli processed with different methods yielding various perceived auditory distances in the vicinity of the listeners. Two different configurations of non-linear amplification were implemented, and a novel feature aiming to restore a sense of distance in wireless microphone systems was tested. The results showed that the hearing-impaired listeners, even those with a profound hearing loss, were able to discriminate nearby and far sounds that were equalized in level. Their perception of auditory distance was however more contracted than in normal-hearing listeners. Non-linear amplification was found to distort the original spatial cues, but no adverse effect on the ratings of auditory distance was evident. Finally, it was shown that the novel feature was successful in allowing the hearing-impaired participants to perceive externalized sounds with wireless microphone systems.


2005 ◽  
Vol 48 (3) ◽  
pp. 702-714 ◽  
Author(s):  
Peninah S. Rosengard ◽  
Karen L. Payton ◽  
Louis D. Braida

The purpose of this study was twofold: (a) to determine the extent to which 4-channel, slow-acting wide dynamic range amplitude compression (WDRC) can counteract the perceptual effects of reduced auditory dynamic range and (b) to examine the relation between objective measures of speech intelligibility and categorical ratings of speech quality for sentences processed with slow-acting WDRC. Multiband expansion was used to simulate the effects of elevated thresholds and loudness recruitment in normal hearing listeners. While some previous studies have shown that WDRC can improve both speech intelligibility and quality, others have found no benefit. The current experiment shows that moderate amounts of compression can provide a small but significant improvement in speech intelligibility, relative to linear amplification, for simulated-loss listeners with small dynamic ranges (i.e., flat, moderate hearing loss). This benefit was found for speech at conversational levels, both in quiet and in a background of babble. Simulated-loss listeners with large dynamic ranges (i.e., sloping, mild-to-moderate hearing loss) did not show any improvement. Comparison of speech intelligibility scores and subjective ratings of intelligibility showed that listeners with simulated hearing loss could accurately judge the overall intelligibility of speech. However, in all listeners, ratings of pleasantness decreased as the compression ratio increased. These findings suggest that subjective measures of speech quality should be used in conjunction with either objective or subjective measures of speech intelligibility to ensure that participant-selected hearing aid parameters optimize both comfort and intelligibility.


1994 ◽  
Vol 37 (3) ◽  
pp. 655-661 ◽  
Author(s):  
Pamela E. Souza ◽  
Christopher W. Turner

This study examined the contributions of various properties of background noise to the speech recognition difficulties experienced by young and elderly listeners with hearing loss. Three groups of subjects participated: young listeners with normal hearing, young listeners with sensorineural hearing loss, and elderly listeners with sensorineural hearing loss. Sensitivity thresholds up to 4000 Hz of the young and elderly groups of listeners with hearing loss were closely matched, and a high-pass masking noise was added to minimize the contributions of high-frequency (above 4000 Hz) thresholds, which were not closely matched. Speech recognition scores for monosyllables were obtained in the high-pass noise alone and in three noise backgrounds. The latter consisted of high-pass noise plus one of three maskers: speechspectrum noise, speech-spectrum noise temporally modulated by the envelope of multi-talker babble, and multi-talker babble. For all conditions, the groups with hearing impairment consistently scored lower than the group with normal hearing. Although there was a trend toward poorer speech-recognition scores as the masker condition more closely resembled the speech babble, the effect of masker condition was not statistically significant. There was no interaction between group and condition, implying that listeners with normal hearing and listeners with hearing loss are affected similarly by the type of background noise when the long-term spectrum of the masker is held constant. A significant effect of age was not observed. In addition, masked thresholds for pure tones in the presence of the speech-spectrum masker were not different for the young and elderly listeners with hearing loss. These results suggest that, for both steady-state and modulated background noises, difficulties in speech recognition for monosyllables are due primarily, and perhaps exclusively, to the presence of sensorineural hearing loss itself, and not to age-specific factors.


1986 ◽  
Vol 29 (2) ◽  
pp. 170-178 ◽  
Author(s):  
David A. Fabry ◽  
Dianne J. Van Tasell

Hearing threshold configuration of the impaired ear was simulated via two different methods in the normal ear of each of 6 subjects with unilateral sensorineural hearing loss. The two hearing loss simulation methods were (a) frequency-specific attenuation (filtering), and (b) masking by shaped masking noise. Identification responses to 20 consonant-vowel nonsense syllables were obtained from the normal ear of each subject in the two hearing loss simulation conditions, as well as from the impaired ear. Speech data were scored both for overall percent correct consonant recognition and for error patterns on a set Of eight consonant features. The computed correlation between gross error difference scores and a similarity metric for feature error pattern was essentially zero, indicating that these may be relatively independent measures of speech recognition, and thus may reflect different aspects Of subjects' behavior. For 3 subjects, both masking and filtering successfully simulated the effects of sensorineural hearing loss on consonant feature error patterns. For 1 subject, only filtering produced feature error patterns similar to those of the impaired ear. For the remaining subjects, neither simulation was successful.


1970 ◽  
Vol 13 (2) ◽  
pp. 426-437 ◽  
Author(s):  
Ellen S. Martin ◽  
J. M. Pickett

Pure-tone auditory thresholds were obtained in quiet and in three levels of masking noise for one normal-hearing group and five groups of subjects with different degrees of sensorineural loss. The masker was a low-pass noise, cut off at 250 Hz. It was presented at overall levels of 77, 97, and 107 dB SPL. Pure-tone thresholds were obtained at test frequencies within and above the masking band. A measure of noise rejection slope was used to describe spread of masking. Degree of loss, configuration of loss, and level of masking noise appear to have marked influences on upward spread of masking patterns in sensorineural subjects.


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