scholarly journals Contributions of Low- and High-Frequency Sensorineural Hearing Deficits to Speech Intelligibility in Noise

2018 ◽  
Author(s):  
Sarah Verhulst ◽  
Anna Warzybok

ABSTRACTThe degree to which supra-threshold hearing deficits affect speech recognition in noise is poorly understood. To clarify the role of hearing sensitivity in different stimulus frequency ranges, and to test the contribution of low- and high-pass speech information to broadband speech recognition, we collected speech reception threshold (SRTs) for low-pass (LP < 1.5 kHz), high-pass (HP > 1.6 kHz) and broadband (BB) speech-in-noise stimuli in 34 listeners. Two noise types with similar long-term spectra were considered: stationary (SSN) and temporally modulated noise (ICRA5-250). Irrespective of the tested listener group (i.e., young normal-hearing, older normal- or impaired-hearing), the BB SRT performance was strongly related to the LP SRT. The encoding of LP speech information was different for SSN and ICRA5-250 noise but similar for HP speech, suggesting a single noise-type invariant coding mechanism for HP speech. Masking release was observed for all filtered conditions and related to the ICRA5-250 SRT. Lastly, the role of hearing sensitivity to the SRT was studied using the speech intelligibility index (SII), which failed to predict the SRTs for the filtered speech conditions and for the older normal-hearing listeners. This suggests that supra-threshold hearing deficits are important contributors to the SRT of older normal-hearing listeners.

1995 ◽  
Vol 38 (1) ◽  
pp. 222-233 ◽  
Author(s):  
Laurie S. Eisenberg ◽  
Donald D. Dirks ◽  
Theodore S. Bell

The effect of amplitude-modulated (AM) noise on speech recognition in listeners with normal and impaired hearing was investigated in two experiments. In the first experiment, nonsense syllables were presented in high-pass steady-state or AM noise to determine whether the release from masking in AM noise relative to steady-state noise was significantly different between normal-hearing and hearing-impaired subjects when the two groups listened under equivalent masker conditions. The normal-hearing subjects were tested in the experimental noise under two conditions: (a) in a spectrally shaped broadband noise that produced pure tone thresholds equivalent to those of the hearing-impaired subjects, and (b) without the spectrally shaped broadband noise. The release from masking in AM noise was significantly greater for the normal-hearing group than for either the hearing-impaired or masked normal-hearing groups. In the second experiment, normal-hearing and hearing-impaired subjects identified nonsense syllables in isolation and target words in sentences in steady-state or AM noise adjusted to approximate the spectral shape and gain of a hearing aid prescription. The release from masking was significantly less for the subjects with impaired hearing. These data suggest that hearingimpaired listeners obtain less release from masking in AM noise than do normal-hearing listeners even when both the speech and noise are presented at levels that are above threshold over much of the speech frequency range.


2020 ◽  
Vol 24 ◽  
pp. 233121652097563
Author(s):  
Christopher F. Hauth ◽  
Simon C. Berning ◽  
Birger Kollmeier ◽  
Thomas Brand

The equalization cancellation model is often used to predict the binaural masking level difference. Previously its application to speech in noise has required separate knowledge about the speech and noise signals to maximize the signal-to-noise ratio (SNR). Here, a novel, blind equalization cancellation model is introduced that can use the mixed signals. This approach does not require any assumptions about particular sound source directions. It uses different strategies for positive and negative SNRs, with the switching between the two steered by a blind decision stage utilizing modulation cues. The output of the model is a single-channel signal with enhanced SNR, which we analyzed using the speech intelligibility index to compare speech intelligibility predictions. In a first experiment, the model was tested on experimental data obtained in a scenario with spatially separated target and masker signals. Predicted speech recognition thresholds were in good agreement with measured speech recognition thresholds with a root mean square error less than 1 dB. A second experiment investigated signals at positive SNRs, which was achieved using time compressed and low-pass filtered speech. The results demonstrated that binaural unmasking of speech occurs at positive SNRs and that the modulation-based switching strategy can predict the experimental results.


1978 ◽  
Vol 21 (1) ◽  
pp. 5-36 ◽  
Author(s):  
Marilyn D. Wang ◽  
Charlotte M. Reed ◽  
Robert C. Bilger

It has been found that listeners with sensorineural hearing loss who show similar patterns of consonant confusions also tend to have similar audiometric profiles. The present study determined whether normal listeners, presented with filtered speech, would produce consonant confusions similar to those previously reported for the hearing-impaired listener. Consonant confusion matrices were obtained from eight normal-hearing subjects for four sets of CV and VC nonsense syllables presented under six high-pass and six low-pass filtering conditions. Patterns of consonant confusion for each condition were described using phonological features in a sequential information analysis. Severe low-pass filtering produced consonant confusions comparable to those of listeners with high-frequency hearing loss. Severe high-pass filtering gave a result comparable to that of patients with flat or rising audiograms. And, mild filtering resulted in confusion patterns comparable to those of listeners with essentially normal hearing. An explanation in terms of the spectrum, the level of speech, and the configuration of the individual listener’s audiogram is given.


1996 ◽  
Vol 39 (2) ◽  
pp. 239-250 ◽  
Author(s):  
Ronald A. van Buuren ◽  
Joost M. Festen ◽  
Tammo Houtgast

In a series of experiments, we introduced peaks of 10, 20, and 30 dB, in various combinations, onto a smooth reference frequency response. For each of the conditions, we evaluated speech intelligibility in noise, using a test as developed by Plomp and Mimpen (1979), and sound quality (for both speech and music), using a rating-scale procedure. We performed the experiments with 26 listeners with sensorineurally impaired hearing and 10 listeners with normal hearing. Signal processing was accomplished digitally; for each listener, the stimuli were filtered and subsequently amplified so that the average speech spectrum was well above the threshold of hearing at all frequencies. The results show that, as a result of the introduction of peaks onto the frequency response, speech intelligibility is affected more for the listeners with impaired hearing than for those with normal hearing. Sound-quality judgments tend to be less different between the listener groups. Conditions with 30-dB peaks especially show serious effects on both speech intelligibility and sound quality.


1967 ◽  
Vol 10 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Charles Speaks

The effects of frequency filtering on intelligibility of synthetic sentences were studied on three normal-hearing listeners. Performance-intensity (P-I) functions were defined for several low-pass and high-pass frequency bands. The data were analyzed to determine the interactions of signal level and frequency range on performance. Intelligibility of synthetic sentences was found to be quite dependent upon low-frequency energy. The important frequency for identification of the materials was approximately 725 Hz. These results are compared with previous findings concerning the intelligibility of single words in quiet and in noise.


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.


2014 ◽  
Vol 25 (06) ◽  
pp. 529-540 ◽  
Author(s):  
Erin C. Schafer ◽  
Danielle Bryant ◽  
Katie Sanders ◽  
Nicole Baldus ◽  
Katherine Algier ◽  
...  

Background: Several recent investigations support the use of frequency modulation (FM) systems in children with normal hearing and auditory processing or listening disorders such as those diagnosed with auditory processing disorders, autism spectrum disorders, attention-deficit hyperactivity disorder, Friedreich ataxia, and dyslexia. The American Academy of Audiology (AAA) published suggested procedures, but these guidelines do not cite research evidence to support the validity of the recommended procedures for fitting and verifying nonoccluding open-ear FM systems on children with normal hearing. Documenting the validity of these fitting procedures is critical to maximize the potential FM-system benefit in the abovementioned populations of children with normal hearing and those with auditory-listening problems. Purpose: The primary goal of this investigation was to determine the validity of the AAA real-ear approach to fitting FM systems on children with normal hearing. The secondary goal of this study was to examine speech-recognition performance in noise and loudness ratings without and with FM systems in children with normal hearing sensitivity. Research Design: A two-group, cross-sectional design was used in the present study. Study Sample: Twenty-six typically functioning children, ages 5–12 yr, with normal hearing sensitivity participated in the study. Intervention: Participants used a nonoccluding open-ear FM receiver during laboratory-based testing. Data Collection and Analysis: Participants completed three laboratory tests: (1) real-ear measures, (2) speech recognition performance in noise, and (3) loudness ratings. Four real-ear measures were conducted to (1) verify that measured output met prescribed-gain targets across the 1000–4000 Hz frequency range for speech stimuli, (2) confirm that the FM-receiver volume did not exceed predicted uncomfortable loudness levels, and (3 and 4) measure changes to the real-ear unaided response when placing the FM receiver in the child’s ear. After completion of the fitting, speech recognition in noise at a –5 signal-to-noise ratio and loudness ratings at a +5 signal-to-noise ratio were measured in four conditions: (1) no FM system, (2) FM receiver on the right ear, (3) FM receiver on the left ear, and (4) bilateral FM system. Results: The results of this study suggested that the slightly modified AAA real-ear measurement procedures resulted in a valid fitting of one FM system on children with normal hearing. On average, prescriptive targets were met for 1000, 2000, 3000, and 4000 Hz within 3 dB, and maximum output of the FM system never exceeded and was significantly lower than predicted uncomfortable loudness levels for the children. There was a minimal change in the real-ear unaided response when the open-ear FM receiver was placed into the ear. Use of the FM system on one or both ears resulted in significantly better speech recognition in noise relative to a no-FM condition, and the unilateral and bilateral FM receivers resulted in a comfortably loud signal when listening in background noise. Conclusions: Real-ear measures are critical for obtaining an appropriate fit of an FM system on children with normal hearing.


2013 ◽  
Vol 109 (6) ◽  
pp. 1658-1668 ◽  
Author(s):  
Daniel J. Tollin ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin

Sound localization along the azimuthal dimension depends on interaural time and level disparities, whereas localization in elevation depends on broadband power spectra resulting from the filtering properties of the head and pinnae. We trained cats with their heads unrestrained, using operant conditioning to indicate the apparent locations of sounds via gaze shift. Targets consisted of broadband (BB), high-pass (HP), or low-pass (LP) noise, tones from 0.5 to 14 kHz, and 1/6 octave narrow-band (NB) noise with center frequencies ranging from 6 to 16 kHz. For each sound type, localization performance was summarized by the slope of the regression relating actual gaze shift to desired gaze shift. Overall localization accuracy for BB noise was comparable in azimuth and in elevation but was markedly better in azimuth than in elevation for sounds with limited spectra. Gaze shifts to targets in azimuth were most accurate to BB, less accurate for HP, LP, and NB sounds, and considerably less accurate for tones. In elevation, cats were most accurate in localizing BB, somewhat less accurate to HP, and less yet to LP noise (although still with slopes ∼0.60), but they localized NB noise much worse and were unable to localize tones. Deterioration of localization as bandwidth narrows is consistent with the hypothesis that spectral information is critical for sound localization in elevation. For NB noise or tones in elevation, unlike humans, most cats did not have unique responses at different frequencies, and some appeared to respond with a “default” location at all frequencies.


2004 ◽  
Vol 47 (5) ◽  
pp. 965-978 ◽  
Author(s):  
Richard A. Roberts ◽  
Jennifer J. Lister

Older listeners with normal-hearing sensitivity and impaired-hearing sensitivity often demonstrate poorer-than-normal performance on tasks of speech understanding in noise and reverberation. Deficits in temporal resolution and in the precedence effect may underlie this difficulty. Temporal resolution is often studied by means of a gap-detection paradigm. This task is similar to binaural fusion paradigms used to measure the precedence effect. The purpose of this investigation was to determine if within-channel (measured with monotic and diotic gap detection) or across-channel (measured with dichotic gap detection) temporal resolution is related to fusion (measured with lag-burst thresholds; LBTs) under dichotic, anechoic, and reverberant conditions. Gap-detection thresholds (GDTs) and LBTs were measured by means of noise-burst stimuli for 3 groups of listeners: young adults with normal-hearing sensitivity (YNH), older adults with normal-hearing sensitivity (ONH), and older adults with impaired-hearing sensitivity (OIH). The GDTs indicated that across-channel temporal resolution is poorer than within-channel temporal resolution and that the effects of age and hearing loss are dependent on condition. Results for the fusion task indicated higher LBTs in reverberation than for the dichotic and anechoic conditions, regardless of group, and no effect of age or hearing loss for the nonreverberant conditions. However, higher LBTs were observed in the reverberant condition for the ONH listeners. Further, there was a correlation between across-channel temporal resolution and fusion in reverberation. Gap detection and fusion may not necessarily reflect the same underlying processes; however, across-channel gap detection may influence fusion under certain conditions (i.e., in reverberation).


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