Author: Carl C. Crandell
Publisher:
ISBN:
Category :
Languages : en
Pages : 322

View

Book Description

Author: Jeffrey Forrest Havens
Publisher:
ISBN:
Category :
Languages : en
Pages : 314

View

Book Description

Author: Judith Suzanne Gravel
Publisher:
ISBN:
Category : Hearing impaired
Languages : en
Pages : 372

View

Book Description

Author: Victoria Stenbäck
Publisher: Linköping University Electronic Press
ISBN: 9176856046
Category :
Languages : en
Pages : 72

View

Book Description
Age affects hearing and cognitive abilities. Older people, with and without hearing impairment (HI), exhibit difficulties in hearing speech in noise. Elderly individuals show greater difficulty in segregating target speech from distracting background noise, especially if the noise is competing speech with meaningful contents, so called informational maskers. Working memory capacity (WMC) has proven to be a crucial factor in comprehending speech in noise, especially for people with hearing loss. In auditory scenes where speech is disrupted by competing speech, high WMC has proven to facilitate the ability to segregate target speech and inhibit responses to irrelevant information. People with low WMC are more prone to be disrupted by competing speech and exhibit more difficulties in hearing target speech in complex listening environments. Furthermore, elderly individuals with a HI experience more difficulties in switching attention between wanted and irrelevant stimuli, and they employ more resources and time to attend to the stimuli than do normally - hearing (NH) younger adults. This thesis investigated the importance of inhibitory control and WMC for speech recognition in noise, and perceived listening effort. Four studies were conducted. In the first study, the aim was to develop a test of inhibitory control for verbal content, and to investigate the relation between inhibitory control and WMC, and how these two abilities related to speech recognition in noise, in young normally – hearing (YNH) individuals. In the second study we aimed to investigate the same relationship as in the first study to further strengthen the validity of the inhibitory test developed, as well as the importance of lexical access. It was also an aim to investigate the influence of age and hearing status on lexical access and WMC, and their respective roles for speech recognition in noise in both YNH and elderly HI (EHI) individuals. Study one and two showed that, for YNH, inhibitory control was related to speech recognition in noise, indicating that inhibitory control can help to predict speech recognition in noise performance. The relationship between WMC and speech recognition in noise in YNH shifted in the studies, suggesting that this relationship is multifaceted and varying. Lexical access was of little importance for YNH, although for EHI individuals, both WMC and lexical access was of importance for speech recognition in noise, suggesting that different cognitive abilities were of importance for the YNH and EHI individuals Study three investigated the relationship between inhibitory control, WMC, speech recognition in noise, and perceived listening effort, in YNH and elderly, for their age, NH, individuals (ENH). In study four the same relationships as in study three were investigated, albeit in EHI individuals. Two speech materials with different characteristics, masked with four background noises were used. The results in study three showed that less favourable SNRs were needed for informational maskers than for maskers without semantic content. ENH individuals were more susceptible to informational maskers than YNH individuals. In contrast, in study four, more favourable SNRs were needed for informational maskers. In both studies, results showed that speech recognition in noise performance differed depending on the characteristics of the speech material. The studies showed that high WMC, compared to low WMC, was beneficial for speech recognition in noise, especially for informational maskers, and resulted in lower ratings of perceived effort. Varying results were found in study three and four regarding perceived effort and inhibitory control. In study three good inhibitory control was associated with lower effort rating, while in study four, individuals with a HI and good inhibitory control rated effort as higher. The results suggest that hearing status, age, and cognitive abilities, contribute to the differences in performance between YNH, ENH, and EHI individuals in speech – recognition – in – noise - and cognitive tasks. This thesis has, for the first time, demonstrated that a measure of inhibitory control of verbal content, is related to speech recognition in noise performance in YNH, ENH and EHI individuals. Results presented in this thesis also show that both WMC and inhibitory control are related to an individuals’ perception of how effortful a listening task is. It also adds to the literature that WMC is related to speech recognition in noise performance for ENH and EHI individuals, but that this relationship is not as robust in YNH individuals.

Author: Laura A. D'Aquila
Publisher:
ISBN:
Category :
Languages : en
Pages : 98

View

Book Description
The masking release (MR; i.e., better speech recognition in fluctuating compared to continuous noise backgrounds) that is evident for normal-hearing (NH) listeners is generally reduced or absent in hearing-impaired (HI) listeners. In this study, a signal-processing technique was developed to improve MR in HI listeners and offer insight into the mechanisms influencing the size of MR. This technique compares short-term and long-term estimates of energy, increases the level of short-term segments whose energy is below the average energy, and normalizes the overall energy of the processed signal to be equivalent to that of the original long-term estimate. In consonant-identification tests, HI listeners achieved similar scores for processed and unprocessed stimuli in quiet and in continuous-noise backgrounds, while superior performance was obtained for the processed speech in some of the fluctuating background noises. Thus, the energy-normalized signals led to larger values of MR compared to that obtained with unprocessed signals.

Author: Sven Mattys
Publisher: Psychology Press
ISBN: 1317836812
Category : Psychology
Languages : en
Pages : 326

View

Book Description
Speech recognition in ‘adverse conditions’ has been a familiar area of research in computer science, engineering, and hearing sciences for several decades. In contrast, most psycholinguistic theories of speech recognition are built upon evidence gathered from tasks performed by healthy listeners on carefully recorded speech, in a quiet environment, and under conditions of undivided attention. Building upon the momentum initiated by the Psycholinguistic Approaches to Speech Recognition in Adverse Conditions workshop held in Bristol, UK, in 2010, the aim of this volume is to promote a multi-disciplinary, yet unified approach to the perceptual, cognitive, and neuro-physiological mechanisms underpinning the recognition of degraded speech, variable speech, speech experienced under cognitive load, and speech experienced by theoretically relevant populations. This collection opens with a review of the literature and a formal classification of adverse conditions. The research articles then highlight those adverse conditions with the greatest potential for constraining theory, showing that some speech phenomena often believed to be immutable can be affected by noise, surface variations, or attentional set in ways that will force researchers to rethink their theory. This volume is essential for those interested in speech recognition outside laboratory constraints.

Author: Eric M. Johnson
Publisher:
ISBN:
Category : Hearing disorders
Languages : en
Pages : 0

View

Book Description
The three manuscripts presented here examine concepts related to speech perception in noise and ways to overcome poor speech intelligibility without depriving listeners of environmental sound recognition. Because of hearing-impaired (HI) listeners’ auditory deficits, there is a substantial need for speech-enhancement (noise reduction) technology. Recent advancements in deep learning have resulted in algorithms that significantly improve the intelligibility of speech in noise, but in order to be suitable for real-world applications such as hearing aids and cochlear implants, these algorithms must be causal, talker independent, corpus independent, and noise independent. Manuscript 1 involves human-subjects testing of a novel, time-domain-based algorithm that fulfills these fundamental requirements. Algorithm processing resulted in significant intelligibility improvements for both HI and normal-hearing (NH) listener groups in each signal-to-noise ratio (SNR) and noise type tested. In Manuscript 2, the range of speech-to-background ratios (SBRs) over which NH and HI listeners can accurately perform both speech and environmental recognition was determined. Separate groups of NH listeners were tested in conditions of selective and divided attention. A single group of HI listeners was tested in the divided attention experiment. Psychometric functions were generated for each listener group and task type. It was found that both NH and HI listeners are capable of high speech intelligibility and high environmental sound recognition over a range of speech-to-background ratios. The range and location of optimal speech-to-background ratios differed across NH and HI listeners. The optimal speech-to-background ratio also depended on the type of environmental sound present. Conventional deep-learning algorithms for speech enhancement target maximum intelligibly by removing as much noise as possible while maintaining the essential characteristics of the target speech signal. Manuscript 3 tests a new form of time-frequency masking that is designed to leave a small amount of background noise intact. The purpose of the unremoved background noise is to allow for environmental sound awareness while still providing significantly increased intelligibility. It was found that this type of processing resulted in significantly improved intelligibility and high environmental sound recognition performance for both types of listeners. It was also found that the same level of maximum attenuation provided the optimal balance of intelligibility and environmental sound recognition for both listener types.

Author:
Publisher:
ISBN:
Category : Audiology
Languages : en
Pages : 242

View

Book Description

Author: Thomas Richard Crain
Publisher:
ISBN:
Category :
Languages : en
Pages : 212

View

Book Description

Author: Riya O. Singh
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
This research investigates the longstanding problem of understanding human speech perception. We aim to study speech perception and decode perceptual cues in speech by conducting psychoacoustic experiments on several subjects by presenting them with nonsense consonant-vowel (CV) syllables in various kinds of masking noise at di fferent signal-to-noise ratios (SNRs). Our research with a large number of normal hearing (NH) listeners shows that NH speech perception is deterministic and the error is essentially zero when the main perceptual feature (or event) of the utterance is audible. With the perceptual CV cues precisely known, one can predict how an average normal hearing (ANH) listener would behave in a certain type and degree of masking noise. The next major goal of the current research is to characterize hearing-impaired (HI) ears by using our knowledge of specific consonant speech cues in ANH ears, thus quantifying how the HI ears di ffer from ANH ears in their use of acoustic cues. Our analysis shows that HI ears may have poor temporal and/or frequency resolution, because of which they are unable to hear only a few consonants, yet they can hear the rest. We argue that it is necessary to measure this consonant dependence in order to design a more sensitive hearing aid fi tting technique, and no other clinical measure used currently (audiometry, average speech recognition scores, speech in noise tests) is useful in characterizing speech-loss, in HI ears. We measured 46 HI ears with our CV discrimination test using the current hearing aid amplifi cation technique NAL-R; the results show that though NAL-R improves the aver- age score, it degrades a few consonants under certain circumstances. This research also addresses the important issue of cochlear dead regions, which are places along the basilar membrane of the cochlea where the inner hair cells are degenerate. We propose a new method to diagnose dead regions based on comodulation masking release. This project extends our effort to achieve a fundamental insight into the nature of both ANH and HI speech perception, enabling the design of hearing aids that are functionally useful in high ambient noise and that help make audible the sounds that the HI ear could not hear previously, without aff ecting the sounds that they can hear.