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Pamela E. Souza - One of the best experts on this subject based on the ideXlab platform.
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the role of spectral resolution working memory and Audibility in explaining variance in susceptibility to temporal envelope distortion
Journal of The American Academy of Audiology, 2014Co-Authors: Evelyn E Daviesvenn, Pamela E. SouzaAbstract:BACKGROUND Several studies have shown that hearing thresholds alone cannot adequately predict listeners' success with hearing-aid amplification. Furthermore, previous studies have shown marked differences in listeners' susceptibility to distortions introduced by certain nonlinear amplification parameters. PURPOSE The purpose of this study was to examine the role of spectral resolution, working memory, and Audibility in explaining perceptual susceptibility to temporal envelope and other hearing-aid compression-induced distortions for listeners with mild to moderate and moderate to severe hearing loss. RESEARCH DESIGN A between-subjects repeated-measures design was used to compare speech recognition scores with linear versus compression amplification, for listeners with mild to moderate and moderate to severe hearing loss. STUDY SAMPLE The study included 15 adult listeners with mild to moderate hearing loss and 13 adults with moderate to severe hearing loss. DATA COLLECTION/ANALYSIS Speech recognition scores were measured for vowel-consonant-vowel syllables processed with linear, moderate compression, and extreme compression amplification. Perceptual susceptibility to compression-induced temporal envelope distortion was defined as the difference in scores between linear and compression amplification. Both overall scores and consonant feature scores (i.e., place, manner, and voicing) were analyzed. Narrowband spectral resolution was measured using individual measures of auditory filter bandwidth at 2000 Hz. Working memory was measured using the reading span test. Signal Audibility was quantified using the Aided Audibility Index. Multiple linear regression was used to determine the predictive role of spectral resolution, working memory, and Audibility benefit on listeners' susceptibility to compression-induced distortions. RESULTS For all listeners, spectral resolution, working memory, and Audibility benefit were significant predictors of overall distortion scores. For listeners with moderate to severe hearing loss, spectral resolution and Audibility benefit predicted distortion scores for consonant place and manner of articulation features, and Audibility benefit predicted distortion scores for consonant voicing features. For listeners with mild to moderate hearing loss, the model did not predict distortion scores for overall or consonant feature scores. CONCLUSIONS The results from this study suggest that when Audibility is adequately controlled, measures of spectral resolution may identify the listeners who are most susceptible to compression-induced distortions. Working memory appears to modulate the negative effect of these distortions for listeners with moderate to severe hearing loss.
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effects of Audibility and multichannel wide dynamic range compression on consonant recognition for listeners with severe hearing loss
Ear and Hearing, 2009Co-Authors: Evelyn E Daviesvenn, Pamela E. Souza, Marc A. Brennan, Christopher G SteckerAbstract:Objective: This study examined the effects of multichannel wide-dynamic range compression (WDRC) amplification and stimulus Audibility on consonant recognition and error patterns. Design: Listeners had either severe or mild to moderate sensorineural hearing loss. Each listener was monaurally fit with a wearable hearing aid using typical clinical procedures, frequency-gain parameters, and a hybrid of clinically prescribed compression ratios for desired sensation level (Scollie et al., 2005) and NAL-NL (Dillon, 1999). Consonant-vowel nonsense syllables were presented in soundfield at multiple input levels (50, 65, 80 dB SPL). Test conditions were four-channel fast-acting WDRC amplification and a control compression limiting (CL) amplification condition. Listeners identified the stimulus heard from choices presented on an on-screen display. A between-subject repeated measures design was used to evaluate consonant recognition and consonant confusion patterns. Results: Fast-acting WDRC provided a considerable Audibility advantage at 50 dB SPL, especially for listeners with severe hearing loss. Listeners with mild to moderate hearing loss received less Audibility improvement from the fast-acting WDRC amplification, for conversational and high level speech, when compared with listeners with severe hearing loss. Analysis of WDRC benefit scores revealed that listeners had slightly lower scores with fast-acting WDRC amplification (relative to CL) when WDRC provided minimal improvement in Audibility. The negative effect was greater for listeners with mild to moderate hearing loss compared with their counterparts with severe hearing loss. Conclusions: All listeners, but particularly the severe loss group, benefited from fast-acting WDRC amplification for low-level speech. For conversational and higher speech levels (i.e., when WDRC does not confer a significant Audibility advantage), fast-acting WDRC amplification seems to slightly degrade performance. Listeners' consonant confusion patterns suggest that this negative effect may be partly due to fast-acting WDRC-induced distortions, which alter specific consonant features. In support of this view, Audibility accounted for a greater percentage of the variance in listeners' performance with CL amplification compared with fast-acting WDRC amplification.
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Effects of Expansion on Consonant Recognition and Consonant Audibility
Journal of the American Academy of Audiology, 2009Co-Authors: Marc A. Brennan, Pamela E. SouzaAbstract:Background—Hearing aid expansion is intended to reduce the gain for low-level noise. However, expansion can also degrade low-intensity speech. Although it has been suggested that the poorer performance with expansion is due to reduced Audibility, this has not been measured directly. Furthermore, previous studies used relatively high expansion kneepoints. Purpose—This study compared the effect of a 30 dB SPL and 50 dB SPL expansion kneepoint on consonant Audibility and recognition. Research Design—Eight consonant-vowel syllables were presented at 50, 60, and 71 dB SPL. Recordings near the tympanic membrane were made of each speech token and used to calculate the Aided Audibility Index (AAI). Study Sample—Thirteen subjects with mild to moderate sensorineural hearing loss. Results—Expansion with a high kneepoint resulted in reduced consonant recognition. The AAI correlated significantly with consonant recognition across all conditions and subjects. Conclusion—If consonant recognition is the priority, Audibility calculations could be used to determine an optimal expansion kneepoint for a given individual.
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prediction of speech recognition from Audibility in older listeners with hearing loss effects of age amplification and background noise
Journal of The American Academy of Audiology, 2007Co-Authors: Pamela E. Souza, Kumiko T Boike, Kerry Witherell, Kelly L TremblayAbstract:The extent to which Audibility determines speech recognition depends on a number of signal and listener factors. This study focused on three factors: age, background noise modulation, and linear versus wide-dynamic compression amplification. Three audiometrically matched groups of older listeners with hearing loss were tested to determine at what age performance declined relative to that expected on the basis of Audibility. Recognition fell below predicted scores by greater amounts as age increased. Scores were higher for steady versus amplitude-modulated noise. Scores for WDRC-amplified speech were slightly lower than for linearly amplified speech across all groups and noise conditions. We found no interaction between age and type of noise. The small reduction in scores for amplitude-modulated compared to steady noise and lack of age interaction suggests that the substantial deficit seen with age in multitalker babble for previous studies was due to some effect not elicited here, such as informational masking.
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effect of preferred volume setting on speech Audibility in different hearing aid circuits
Journal of The American Academy of Audiology, 2001Co-Authors: Pamela E. Souza, Virginia KitchAbstract:This study compared preferred volume setting for linear peak clipping, compression limiting, and wide dynamic range compression (WDRC) amplification and quantified speech Audibility at the preferred volume setting for each amplification type. Ten listeners with mild-to-moderate hearing loss were fitted monaurally with a behind-the-ear hearing aid programmed sequentially with WDRC, compression limiting, and linear peak clipping amplification. Speech was presented in quiet and in noise at a range of input levels. In each condition, the listener adjusted the volume for maximum clarity. Signal levels were measured using a probe microphone system. There was no significant difference in speech Audibility between amplification strategies for any speech level regardless of the presence or absence of background noise. These results imply that the improved Audibility advantage of WDRC over linear amplification demonstrated in controlled environments may not be maintained in situations where the hearing aid wearer controls the volume.
Teresa Y. C. Ching - One of the best experts on this subject based on the ideXlab platform.
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hearing aid fitting and developmental outcomes of children fit according to either the nal or dsl prescription fit to target Audibility speech and language abilities
International Journal of Audiology, 2018Co-Authors: Teresa Y. C. Ching, Earl E. Johnson, Vicky Zhang, Patricia Van Buynder, Sanna Hou, Lauren Burns, Laura Button, Christopher Flynn, Karen McghieAbstract:AbstractObjective: This study examined the influence of prescription on hearing aid (HA) fitting characteristics and 5-year developmental outcomes of children. Design: A randomised controlled trial implemented as part of a population-based study on Longitudinal Outcomes of Children with Hearing Impairment (LOCHI). Study sample: Two-hundred and thirty-two children that were fit according to either the National Acoustic Laboratories (NAL) or Desired Sensation Level (DSL) prescription. Results: Deviation from targets and root-mean-square error in HA fitting revealed no significant difference between fitting prescriptions. Aided Audibility quantified by using the Speech Intelligibility Index (SII) model showed that DSL provided higher Audibility than NAL at low and medium input levels but not at high input level. After allowing for hearing loss desensitisation, differences in Audibility between prescription groups were significant only at low input level. The randomised trial of prescription that was implemen...
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Audibility and speech intelligibility revisited: implications for amplification
2011Co-Authors: Teresa Y. C. Ching, Harvey Dillon, Frances Lockhart, Emma Van Wanrooy, Matt FlaxAbstract:A major goal of amplification is to restore Audibility to people with hearing loss in as wide a range of frequencies as possible for maximising speech intelligibility. The usefulness of Audibility for speech intelligibility, however, decreases as hearing loss increases. This reduced effectiveness of Audibility may be related to the presence of cochlear dead regions or just to reduced frequency and temporal resolution. In this paper, the current literature that relates the presence of dead regions to usefulness of highfrequency Audibility is examined. This is followed by a brief description of an empirical study that investigated factors affecting speech intelligibility in quiet and in noise by hearing-impaired listeners. A modification of the Speech Intelligibility Index (SII) method that minimised discrepancies between observed and predicted speech intelligibility is presented. Finally, factors that affect speech intelligibility are summarised together with a discussion on implications for amplification.
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Methods and Applications of the Audibility Index in Hearing Aid Selection and Fitting
Trends in amplification, 2002Co-Authors: Amyn M. Amlani, Jerry L. Punch, Teresa Y. C. ChingAbstract:During the first half of the 20th century, communications engineers at Bell Telephone Laboratories developed the articulation model for predicting speech intelligibility transmitted through different telecommunication devices under varying electroacoustic conditions. The profession of audiology adopted this model and its quantitative aspects, known as the Articulation Index and Speech Intelligibility Index, and applied these indices to the prediction of unaided and aided speech intelligibility in hearing-impaired listeners. Over time, the calculation methods of these indices—referred to collectively in this paper as the Audibility Index—have been continually refined and simplified for clinical use. This article provides (1) an overview of the basic principles and the calculation methods of the Audibility Index, the Speech Transmission Index and related indices, as well as the Speech Recognition Sensitivity Model, (2) a review of the literature on using the Audibility Index to predict speech intelligibility of hearing-impaired listeners, (3) a review of the literature on the applicability of the Audibility Index to the selection and fitting of hearing aids, and (4) a discussion of future scientific needs and clinical applications of the Audibility Index.
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Maximizing effective Audibility in hearing aid fitting.
Ear and hearing, 2001Co-Authors: Teresa Y. C. Ching, Harvey Dillon, Richard Katsch, Denis ByrneAbstract:ObjectiveThis paper examines why more Audibility is not always better than less Audibility if hearing-impaired people are to best understand speech.DesignWe used speech perception data from 14 normally hearing and 40 hearing-impaired people to quantify the contribution of Audibility to speech intell
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speech recognition of hearing impaired listeners predictions from Audibility and the limited role of high frequency amplification
Journal of the Acoustical Society of America, 1998Co-Authors: Teresa Y. C. Ching, Harvey Dillon, Denis ByrneAbstract:Two experiments were conducted to examine the relationship between Audibility and speech recognition for individuals with sensorineural hearing losses ranging from mild to profound degrees. Speech scores measured using filtered sentences were compared to predictions based on the Speech Intelligibility Index (SII). The SII greatly overpredicted performance at high sensation levels, and for many listeners, it underpredicted performance at low sensation levels. To improve predictive accuracy, the SII needed to be modified. Scaling the index by a multiplicative proficiency factor was found to be inappropriate, and alternative modifications were explored. The data were best fitted using a method that combined the standard level distortion factor (which accounted for decrease in speech intelligibility at high presentation levels based on measurements of normal-hearing people) with individual frequency-dependent proficiency. This method was evaluated using broadband sentences and nonsense syllables tests. Results indicate that Audibility cannot adequately explain speech recognition of many hearing-impaired listeners. Considerable variations from Audibility-based predictions remained, especially for people with severe losses listening at high sensation levels. The data suggest that, contrary to the basis of the SII, information contained in each frequency band is not strictly additive. The data also suggest that for people with severe or profound losses at the high frequencies, amplification should only achieve a low or zero sensation level at this region, contrary to the implications of the unmodified SII.
Ryan W Mccreery - One of the best experts on this subject based on the ideXlab platform.
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Audibility based hearing aid fitting criteria for children with mild bilateral hearing loss
Language Speech and Hearing Services in Schools, 2020Co-Authors: Ryan W Mccreery, Elizabeth A Walker, Meredith Spratford, Jacob Oleson, Derek J Stiles, Dawna E LewisAbstract:Purpose Because of uncertainty about the level of hearing where hearing aids should be provided to children, the goal of the current study was to develop Audibility-based hearing aid candidacy crit...
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longitudinal predictors of aided speech Audibility in infants and children
Ear and Hearing, 2015Co-Authors: Ryan W Mccreery, Elizabeth A Walker, Meredith Spratford, Ruth Bentler, Lenore Holte, Jacob Oleson, John Van Buren, Patricia A Roush, Mary Pat MoellerAbstract:OBJECTIVES Amplification is a core component of early intervention for children who are hard of hearing, but hearing aids (HAs) have unique effects that may be independent from other components of the early intervention process, such as caregiver training or speech and language intervention. The specific effects of amplification are rarely described in studies of developmental outcomes. The primary purpose of this article is to quantify aided speech Audibility during the early childhood years and examine the factors that influence Audibility with amplification for children in the Outcomes of Children with Hearing Loss study. DESIGN Participants were 288 children with permanent hearing loss who were followed as part of the Outcomes of Children with Hearing Loss study. All of the children in this analysis had bilateral hearing loss and wore air-conduction behind-the-ear HAs. At every study visit, hearing thresholds were measured using developmentally appropriate behavioral methods. Data were obtained for a total of 1043 audiometric evaluations across all subjects for the first four study visits. In addition, the aided Audibility of speech through the HA was assessed using probe microphone measures. Hearing thresholds and aided Audibility were analyzed. Repeated-measures analyses of variance were conducted to determine whether patterns of thresholds and aided Audibility were significantly different between ears (left versus right) or across the first four study visits. Furthermore, a cluster analysis was performed based on the aided Audibility at entry into the study, aided Audibility at the child's final visit, and change in aided Audibility between these two intervals to determine whether there were different patterns of longitudinal aided Audibility within the sample. RESULTS Eighty-four percent of children in the study had stable audiometric thresholds during the study, defined as threshold changes <10 dB for any single study visit. There were no significant differences in hearing thresholds, aided Audibility, or deviation of the HA fitting from prescriptive targets between ears or across test intervals for the first four visits. Approximately 35% of the children in the study had aided Audibility that was below the average for the normative range for the Speech Intelligibility Index based on degree of hearing loss. The cluster analysis of longitudinal aided Audibility revealed three distinct groups of children: a group with consistently high aided Audibility throughout the study, a group with decreasing Audibility during the study, and a group with consistently low aided Audibility. CONCLUSIONS The current results indicated that approximately 65% of children in the study had adequate aided Audibility of speech and stable hearing during the study period. Limited Audibility was associated with greater degrees of hearing loss and larger deviations from prescriptive targets. Studies of developmental outcomes will help to determine how aided Audibility is necessary to affect developmental outcomes in children who are hard of hearing.
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Longitudinal Predictors of Aided Speech Audibility in Infants and Children.
Ear and hearing, 2015Co-Authors: Ryan W Mccreery, Elizabeth A Walker, Meredith Spratford, Ruth Bentler, Lenore Holte, Patricia Roush, Jacob Oleson, John Van Buren, Mary Pat MoellerAbstract:Amplification is a core component of early intervention for children who are hard of hearing, but hearing aids (HAs) have unique effects that may be independent from other components of the early intervention process, such as caregiver training or speech and language intervention. The specific effects of amplification are rarely described in studies of developmental outcomes. The primary purpose of this article is to quantify aided speech Audibility during the early childhood years and examine the factors that influence Audibility with amplification for children in the Outcomes of Children with Hearing Loss study. Participants were 288 children with permanent hearing loss who were followed as part of the Outcomes of Children with Hearing Loss study. All of the children in this analysis had bilateral hearing loss and wore air-conduction behind-the-ear HAs. At every study visit, hearing thresholds were measured using developmentally appropriate behavioral methods. Data were obtained for a total of 1043 audiometric evaluations across all subjects for the first four study visits. In addition, the aided Audibility of speech through the HA was assessed using probe microphone measures. Hearing thresholds and aided Audibility were analyzed. Repeated-measures analyses of variance were conducted to determine whether patterns of thresholds and aided Audibility were significantly different between ears (left versus right) or across the first four study visits. Furthermore, a cluster analysis was performed based on the aided Audibility at entry into the study, aided Audibility at the child's final visit, and change in aided Audibility between these two intervals to determine whether there were different patterns of longitudinal aided Audibility within the sample. Eighty-four percent of children in the study had stable audiometric thresholds during the study, defined as threshold changes <10 dB for any single study visit. There were no significant differences in hearing thresholds, aided Audibility, or deviation of the HA fitting from prescriptive targets between ears or across test intervals for the first four visits. Approximately 35% of the children in the study had aided Audibility that was below the average for the normative range for the Speech Intelligibility Index based on degree of hearing loss. The cluster analysis of longitudinal aided Audibility revealed three distinct groups of children: a group with consistently high aided Audibility throughout the study, a group with decreasing Audibility during the study, and a group with consistently low aided Audibility. The current results indicated that approximately 65% of children in the study had adequate aided Audibility of speech and stable hearing during the study period. Limited Audibility was associated with greater degrees of hearing loss and larger deviations from prescriptive targets. Studies of developmental outcomes will help to determine how aided Audibility is necessary to affect developmental outcomes in children who are hard of hearing.
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Longitudinal Predictors of Aided Speech Audibility in Infants and Children.
Ear & Hearing, 2015Co-Authors: Ryan W Mccreery, Elizabeth A Walker, Meredith Spratford, Ruth Bentler, Lenore Holte, Jacob Oleson, John Van Buren, Patricia A Roush, Mary Pat MoellerAbstract:OBJECTIVES Amplification is a core component of early intervention for children who are hard of hearing, but hearing aids (HAs) have unique effects that may be independent from other components of the early intervention process, such as caregiver training or speech and language intervention. The specific effects of amplification are rarely described in studies of developmental outcomes. The primary purpose of this article is to quantify aided speech Audibility during the early childhood years and examine the factors that influence Audibility with amplification for children in the Outcomes of Children with Hearing Loss study. DESIGN Participants were 288 children with permanent hearing loss who were followed as part of the Outcomes of Children with Hearing Loss study. All of the children in this analysis had bilateral hearing loss and wore air-conduction behind-the-ear HAs. At every study visit, hearing thresholds were measured using developmentally appropriate behavioral methods. Data were obtained for a total of 1043 audiometric evaluations across all subjects for the first four study visits. In addition, the aided Audibility of speech through the HA was assessed using probe microphone measures. Hearing thresholds and aided Audibility were analyzed. Repeated-measures analyses of variance were conducted to determine whether patterns of thresholds and aided Audibility were significantly different between ears (left versus right) or across the first four study visits. Furthermore, a cluster analysis was performed based on the aided Audibility at entry into the study, aided Audibility at the child's final visit, and change in aided Audibility between these two intervals to determine whether there were different patterns of longitudinal aided Audibility within the sample. RESULTS Eighty-four percent of children in the study had stable audiometric thresholds during the study, defined as threshold changes
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the influence of Audibility on speech recognition with nonlinear frequency compression for children and adults with hearing loss
Ear and Hearing, 2014Co-Authors: Ryan W Mccreery, Marc A. Brennan, Joshua M Alexander, Brenda Hoover, Judy G Kopun, Patricia G StelmachowiczAbstract:Objective: The primary goal of nonlinear frequency compression (NFC) and other frequency-lowering strategies is to increase the Audibility of high-frequency sounds that are not otherwise audible with conventional hearing aid (HA) processing due to the degree of hearing loss, limited HA bandwidth, or a combination of both factors. The aim of the present study was to compare estimates of speech Audibility processed by NFC with improvements in speech recognition for a group of children and adults with high-frequency hearing loss. Design: Monosyllabic word recognition was measured in noise for 24 adults and 12 children with mild to severe sensorineural hearing loss. Stimuli were amplified based on each listener’s audiogram with conventional processing (CP) with amplitude compression or with NFC and presented under headphones using a software-based HA simulator. A modification of the speech intelligibility index (SII) was used to estimate Audibility of information in frequency-lowered bands. The mean improvement in SII was compared with the mean improvement in speech recognition. Results: All but 2 listeners experienced improvements in speech recognition with NFC compared with CP, consistent with the small increase in Audibility that was estimated using the modification of the SII. Children and adults had similar improvements in speech recognition with NFC. Conclusion: Word recognition with NFC was higher than CP for children and adults with mild to severe hearing loss. The average improvement in speech recognition with NFC (7%) was consistent with the modified SII, which indicated that listeners experienced an increase in Audibility with NFC compared with CP. Further studies are necessary to determine whether changes in Audibility with NFC are related to speech recognition with NFC for listeners with greater degrees of hearing loss, with a greater variety of compression settings, and using auditory training.
Patricia G Stelmachowicz - One of the best experts on this subject based on the ideXlab platform.
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the influence of Audibility on speech recognition with nonlinear frequency compression for children and adults with hearing loss
Ear and Hearing, 2014Co-Authors: Ryan W Mccreery, Marc A. Brennan, Joshua M Alexander, Brenda Hoover, Judy G Kopun, Patricia G StelmachowiczAbstract:Objective: The primary goal of nonlinear frequency compression (NFC) and other frequency-lowering strategies is to increase the Audibility of high-frequency sounds that are not otherwise audible with conventional hearing aid (HA) processing due to the degree of hearing loss, limited HA bandwidth, or a combination of both factors. The aim of the present study was to compare estimates of speech Audibility processed by NFC with improvements in speech recognition for a group of children and adults with high-frequency hearing loss. Design: Monosyllabic word recognition was measured in noise for 24 adults and 12 children with mild to severe sensorineural hearing loss. Stimuli were amplified based on each listener’s audiogram with conventional processing (CP) with amplitude compression or with NFC and presented under headphones using a software-based HA simulator. A modification of the speech intelligibility index (SII) was used to estimate Audibility of information in frequency-lowered bands. The mean improvement in SII was compared with the mean improvement in speech recognition. Results: All but 2 listeners experienced improvements in speech recognition with NFC compared with CP, consistent with the small increase in Audibility that was estimated using the modification of the SII. Children and adults had similar improvements in speech recognition with NFC. Conclusion: Word recognition with NFC was higher than CP for children and adults with mild to severe hearing loss. The average improvement in speech recognition with NFC (7%) was consistent with the modified SII, which indicated that listeners experienced an increase in Audibility with NFC compared with CP. Further studies are necessary to determine whether changes in Audibility with NFC are related to speech recognition with NFC for listeners with greater degrees of hearing loss, with a greater variety of compression settings, and using auditory training.
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Maximizing Audibility and speech recognition with nonlinear frequency compression by estimating audible bandwidth.
Ear and hearing, 2013Co-Authors: Ryan W Mccreery, Marc A. Brennan, Brenda Hoover, Judy G Kopun, Patricia G StelmachowiczAbstract:Objective Nonlinear frequency compression attempts to restore high-frequency Audibility by lowering high-frequency input signals. Methods of determining the optimal parameters that maximize speech understanding have not been evaluated. The effect of maximizing the audible bandwidth on speech recognition for a group of listeners with normal hearing is described.
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Audibility based predictions of speech recognition for children and adults with normal hearing
Journal of the Acoustical Society of America, 2011Co-Authors: Ryan W Mccreery, Patricia G StelmachowiczAbstract:This study investigated the relationship between Audibility and predictions of speech recognition for children and adults with normal hearing. The Speech Intelligibility Index (SII) is used to quantify the Audibility of speech signals and can be applied to transfer functions to predict speech recognition scores. Although the SII is used clinically with children, relatively few studies have evaluated SII predictions of children’s speech recognition directly. Children have required more Audibility than adults to reach maximum levels of speech understanding in previous studies. Furthermore, children may require greater bandwidth than adults for optimal speech understanding, which could influence frequency-importance functions used to calculate the SII. Speech recognition was measured for 116 children and 19 adults with normal hearing. Stimulus bandwidth and background noise level were varied systematically in order to evaluate speech recognition as predicted by the SII and derive frequency-importance functions for children and adults. Results suggested that children required greater Audibility to reach the same level of speech understanding as adults. However, differences in performance between adults and children did not vary across frequency bands.
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the relation between stimulus context speech Audibility and perception for normal hearing and hearing impaired children
Journal of Speech Language and Hearing Research, 2000Co-Authors: Patricia G Stelmachowicz, Brenda Hoover, Dawna E Lewis, Reinier W L Kortekaas, Andrea L PittmanAbstract:In this study, the influence of stimulus context and Audibility on sentence recognition was assessed in 60 normal-hearing children, 23 hearing-impaired children, and 20 normal-hearing adults. Perfo...
Denis Byrne - One of the best experts on this subject based on the ideXlab platform.
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Maximizing effective Audibility in hearing aid fitting.
Ear and hearing, 2001Co-Authors: Teresa Y. C. Ching, Harvey Dillon, Richard Katsch, Denis ByrneAbstract:ObjectiveThis paper examines why more Audibility is not always better than less Audibility if hearing-impaired people are to best understand speech.DesignWe used speech perception data from 14 normally hearing and 40 hearing-impaired people to quantify the contribution of Audibility to speech intell
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speech recognition of hearing impaired listeners predictions from Audibility and the limited role of high frequency amplification
Journal of the Acoustical Society of America, 1998Co-Authors: Teresa Y. C. Ching, Harvey Dillon, Denis ByrneAbstract:Two experiments were conducted to examine the relationship between Audibility and speech recognition for individuals with sensorineural hearing losses ranging from mild to profound degrees. Speech scores measured using filtered sentences were compared to predictions based on the Speech Intelligibility Index (SII). The SII greatly overpredicted performance at high sensation levels, and for many listeners, it underpredicted performance at low sensation levels. To improve predictive accuracy, the SII needed to be modified. Scaling the index by a multiplicative proficiency factor was found to be inappropriate, and alternative modifications were explored. The data were best fitted using a method that combined the standard level distortion factor (which accounted for decrease in speech intelligibility at high presentation levels based on measurements of normal-hearing people) with individual frequency-dependent proficiency. This method was evaluated using broadband sentences and nonsense syllables tests. Results indicate that Audibility cannot adequately explain speech recognition of many hearing-impaired listeners. Considerable variations from Audibility-based predictions remained, especially for people with severe losses listening at high sensation levels. The data suggest that, contrary to the basis of the SII, information contained in each frequency band is not strictly additive. The data also suggest that for people with severe or profound losses at the high frequencies, amplification should only achieve a low or zero sensation level at this region, contrary to the implications of the unmodified SII.
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Predicting speech intelligibility of hearing‐impaired listeners from Audibility
The Journal of the Acoustical Society of America, 1996Co-Authors: Teresa Y. C. Ching, Harvey Dillon, Denis ByrneAbstract:Speech intelligibility of mild and moderately hearing‐impaired listeners can be successfully accounted for in terms of Audibility, as quantified by the articulation index theory. For people with more severe losses, performance is often overestimated by Audibility. It is hypothesized that deficits in frequency and temporal resolution may be responsible for the reduced ability of these listeners in using an audible signal for speech intelligibility. This study aimed to measure the amount of information that could be extracted from an audible signal by listeners with different degrees of hearing loss at different frequency regions. Twelve normally hearing and 40 hearing‐impaired listeners were tested using filtered sentence material presented at different levels. The results showed that some listeners performed better than normal at low sensation levels but much poorer at high sensation levels. The conventional method of modifying the index by a multiplicative factor would not be appropriate because for many subjects, a smaller factor would be needed at high than at low sensation levels. A modification procedure which incorporates a level‐dependent and frequency‐dependent correction is proposed, and is verified using speech results obtained from sentences and nonsense syllables tests.
