Biomedical subjects

M Kathleen Pichora-Fuller

Publications and source records attributed to M Kathleen Pichora-Fuller.

8 recordsLinked to original sources

PubMed2006

Temporal jitter disrupts speech intelligibility: a simulation of auditory aging.

We disrupted periodicity cues by temporally jittering the speech signal to explore how such distortion might affect word identification. Jittering distorts the fine structure of the speech signal with negligible alteration of either its long-term spectral or amplitude envelope characteristics. In Experiment 1, word identification in noise was significantly reduced in young, normal-hearing adults when sentences were temporally jittered at frequencies below 1.2kHz. The accuracy of the younger adults in identifying jittered speech in noise was similar to that found previously for older adults with good audiograms when they listened to intact speech in noise. In Experiment 2, to rule out the possibility that the reductions in word identification were due to spectral distortion, we also tested a simulation of cochlear hearing loss that produced spectral distortion equivalent to that produced by jittering, but this simulation had significantly less temporal distortion than was produced by jittering. There was no significant reduction in the accuracy of word identification when only the frequency region below 1.2kHz was spectrally distorted. Hence, it is the temporal distortion rather than the spectral distortion of the low-frequency components that disrupts word identification.

Acoustic Stimulation↗

PubMed2006

Providing an internet-based audiological counselling programme to new hearing aid users: a qualitative study.

People with an acquired hearing loss often have difficulty adjusting to a first hearing aid. Studies have shown that audiological counselling can facilitate adjustment to a first hearing aid. Because of its interactive nature, the internet could be a valuable tool to gain information about the experiences of the new hearing aid user and to address the needs for audiological counselling. An internet-based audiological counselling programme in the form of daily e-mails during the first month after the hearing aid fitting was offered to three new hearing aid users. The data, qualitative in nature, were comprised of the content of the e-mails and of in-depth interviews with the participants and their audiologist, and were analysed according to grounded theory. Overall, the internet-based audiological counselling programme provided rich descriptions of the experiences of the participants and reinforced positive adjustment behaviours experienced by them.

Aged↗

PubMed2006

Effect of age on detection of gaps in speech and nonspeech markers varying in duration and spectral symmetry.

Gap detection thresholds for speech and analogous nonspeech stimuli were determined in younger and older adults with clinically normal hearing in the speech range. Gap detection thresholds were larger for older than for younger listeners in all conditions, with the size of the age difference increasing with stimulus complexity. For both ages, gap detection thresholds were far smaller when the markers before and after the gap were the same (spectrally symmetrical) compared to when they were different (spectrally asymmetrical) for both speech and nonspeech stimuli. Moreover, gap detection thresholds were smaller for nonspeech than for speech stimuli when the markers were spectrally symmetrical but the opposite was observed when the markers were spectrally asymmetrical. This pattern of results may reflect the benefit of activating well-learned gap-dependent phonemic contrasts. The stimulus-dependent age effects were interpreted as reflecting the differential effects of age-dependent losses in temporal processing ability on within- and between-channel gap detection.

Adult↗

PubMed2006

Effects of age on auditory and cognitive processing: implications for hearing aid fitting and audiologic rehabilitation.

Recent advances in research and clinical practice concerning aging and auditory communication have been driven by questions about age-related differences in peripheral hearing, central auditory processing, and cognitive processing. A "site-of-lesion'' view based on anatomic levels inspired research to test competing hypotheses about the contributions of changes at these three levels of the nervous system. A "processing'' view based on psychologic functions inspired research to test alternative hypotheses about how lower-level sensory processes and higher-level cognitive processes interact. In the present paper, we suggest that these two views can begin to be unified following the example set by the cognitive neuroscience of aging. The early pioneers of audiology anticipated such a unified view, but today, advances in science and technology make it both possible and necessary. Specifically, we argue that a synthesis of new knowledge concerning the functional neuroscience of auditory cognition is necessary to inform the design and fitting of digital signal processing in "intelligent'' hearing devices, as well as to inform best practices for resituating hearing aid fitting in a broader context of audiologic rehabilitation. Long-standing approaches to rehabilitative audiology should be revitalized to emphasize the important role that training and therapy play in promoting compensatory brain reorganization as older adults acclimatize to new technologies. The purpose of the present paper is to provide an integrated framework for understanding how auditory and cognitive processing interact when older adults listen, comprehend, and communicate in realistic situations, to review relevant models and findings, and to suggest how new knowledge about age-related changes in audition and cognition may influence future developments in hearing aid fitting and audiologic rehabilitation.

Aged↗

PubMed2003

Effects of aging on auditory processing of speech.

The focus of this paper is on the effects of age on speech perception, with reference to pertinent psychoacoustic findings. The difficulties of older listeners are related to the well-known effects of high-frequency hearing loss on speech perception in quiet, and to temporal processing declines not predictable from the audiogram that account for reduced ability to listen in complex, noisy conditions. We also discuss issues of research interpretation; e.g. the need for researchers and clinicians to be alert to the frequent confound between degree of hearing loss and age. The implications of age-related changes in auditory speech processing for future practice and research are discussed relative to interactions between older individuals and their acoustic environments.

Age Factors↗

PubMed2003

Cognitive aging and auditory information processing.

Over the last decade, much research has been conducted to investigate why older listeners report more difficulty in understanding spoken language than would be expected given their degree of audiometric hearing loss. Of particular relevance to audiological rehabilitation is recent research on older listeners when they are engaged in complex tasks involving the auditory processing of naturalistic signals in realistic social and physical environments Discourse epitomizes such activity. By understanding age-related and individual differences in perceptual and cognitive performance, we gain important insights into how hearing impairments influence activity and participation in context. In this paper, the problems of older adults as communicators in everyday life are illuminated by studies showing that auditory processing problems affect cognitive processing. Age-related problems in understanding spoken language are exacerbated by perceptual stressors such as noise and by cognitive stressors such as memory load. It is argued that the significance of these processing problems during discourse depends on social-emotional factors Therefore, goals for new signal-processing technologies designed for older adults who are hard of hearing can be framed not only in terms of improving signal audibility but also in terms of reducing stress on the listener during information processing. Furthermore, goals for therapeutic interventions can be framed in terms of reducing stress during information processing by modifying behaviors and physical and social environments to achieve the listener's goals.

Age Factors↗

PubMed2002

Listening in aging adults: from discourse comprehension to psychoacoustics.

Older adults, whether or not they have clinically significant hearing loss, have more trouble than their younger counterparts understanding speech in everyday life. These age-related difficulties in speech understanding may be attributed to changes in higher-level cognitive processes such as language comprehension, memory, attention, and cognitive slowing, or to lower-level sensory and perceptual processes. A complicating factor in determining how these sources might contribute to age-related declines in speech understanding is that they are highly correlated. Experimenters have typically focused either on cognitive declines or sensory declines in artificially optimized test conditions. In contrast, our approach focuses on the complex interactions between age-related changes in cognitive and perceptual factors that affect spoken language comprehension, especially in nonideal, realistic conditions. In this article, we describe our attempts to systematically investigate sensory-cognitive interactions in controlled experimental situations. We begin by looking at experimental conditions that closely approximate everyday listening, and show that older adults do indeed experience deficits in spoken language comprehension relative to younger adults in these conditions. We then review further experiments designed to isolate more precisely the cognitive and perceptual sources of these age-related differences and how they vary with listening condition. In large part, we find that age-related changes in speech understanding are a consequence of auditory declines.

Aged↗

PubMed2002

Temporally jittered speech produces performance intensity, phonetically balanced rollover in young normal-hearing listeners.

This study investigates whether temporally jittered stimuli will produce performance-intensity, phonetically balanced (PI-PB) rollover in young adults with normal hearing. Although not yet explicitly stated in the literature, there is clinical and theoretical evidence to suggest that PI-PB rollover, such as that found in cases of acoustic neuroma, is caused by neural dyssynchrony in the auditory system. Sixteen participants were tested with intact and temporally jittered word lists in quiet at 40, 55, 65, and uncomfortable listening level -5 dB HL. The results show significant rollover in the jittered but not the intact conditions. The results are consistent with the existing evidence that suggests that neural PI-PB rollover is caused by decreased neural synchrony and support the claim that temporal jitter simulates neural dyssynchrony. Furthermore, these results are consistent with the hypothesis that synchrony coding plays an important role in the perception of high-level speech.

Adolescent↗