Biomedical subjects

A L Strouse

Publications and source records attributed to A L Strouse.

3 recordsLinked to original sources

PubMed1996

Evidence against the influence of aging on distortion-product otoacoustic emissions.

Previous research has reported reduced otoacoustic emission amplitude as a function of age. In each study, however, interpretation of findings was confounded by age-related hearing loss. The present study was designed to re-evaluate the contribution of age and peripheral hearing loss on the prevalence and amplitude of distortion-product otoacoustic emissions (DPOAEs) by controlling for degree of peripheral hearing loss. Twenty subjects were divided into four age ranges. All subjects in each group had 15 dB HL or better thresholds from 0.25 through 8 kHz and normal immittance findings. DPOAE audiograms recorded at three intensity levels and input/output functions recorded at six discrete frequencies showed no significant differences in amplitude or noise level between age groups. Findings indicate that when the degree of peripheral hearing loss is adequately controlled, there is no direct effect of advanced age on DPOAE measures. Clinical implications are discussed.

Acoustic Stimulation↗

PubMed1995

Central auditory processing in Alzheimer's disease.

OBJECTIVE: This investigation was designed to determine whether people in the early to middle phases of Alzheimer's disease (AD) show impaired central auditory processing as compared with nondemented elderly. DESIGN: A peripheral and central auditory test battery was administered to 10 subjects diagnosed with mild-to-moderate AD based on a neuropsychological test battery and radiographic techniques, and a control group of 10 subjects with no evidence of dementia, matched for age, gender, and average degree of hearing loss. Immittance audiometry, pure-tone and speech audiometry, and otoacoustic emissions were recorded in all subjects. Central auditory assessment included the synthetic sentence identification with ipsilateral competing message, dichotic digits, dichotic sentence identification, pitch patterns, and duration patterns. RESULTS: Peripheral auditory status was statistically similar between subject groups. Neither average high frequency hearing sensitivity nor mean speech recognition ability was significantly different. However, a significant difference was noted between groups for average low frequency hearing sensitivity in the left ear (p < 0.05). Subjects with AD showed slightly poorer low frequency thresholds versus matched controls. Based on analysis of performance on each measure of the central auditory test battery, the AD group scored significantly lower than the matched control group on four of the five measures utilized. Differences for right versus left ear performance were found among AD subjects. CONCLUSIONS: Overall patterns in findings cannot be easily explained as artifacts of cognitive decline. Results support screening for central auditory dysfunction in the AD population, since impaired processing could influence psychiatric assessment of cognitive deficit as well as audiologic management of peripheral hearing loss in this population.

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PubMedDate not supplied

Test-retest reliability of a dichotic digits test for assessing central auditory function in Alzheimer's disease.

Test-retest reliability for the dichotic digits test was measured in 10 subjects diagnosed with mild-to-moderate Alzheimer's disease and a control group of 10 subjects with no evidence of dementia, matched for age, gender and average degree of hearing loss. Although initial scores among the Alzheimer group were more variable, test-retest reliability over a month period was reasonably high for both subject groups. Results are in agreement with previous reports on dichotic digits showing good sensitivity, ease in administration and time efficiency. Use of the dichotic digits test for screening of central auditory function in the Alzheimer population is supported.

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