Terrey A. Oliver

Speech Understanding in the Elderly

Both auditory and cognitive status were determined in 130 elderly persons, in the age range from 51 to 91 years. Data were analyzed from the standpoint of the congruence of auditory and cognitive deficits. The prevalence of central auditory processing disorder was 50%, and the prevalence of cognitive deficit was 41%. Findings in the two areas were congruent, however, in only 63% of the total sample. Central auditory status was abnormal in the presence of normal cognitive function in 23% of subjects. Central auditory status was normal in the presence of cognitive deficit in 14% of subjects. In general, results did not support the hypothesis that decline in speech understanding in the elderly can be explained as the consequence of concomitant cognitive decline.

Prediction of dynamic range from stapedius reflex in cochlear implant patients.

Amplitude growth functions of the electrically elicited stapedius reflex were compared with behavioral estimates of dynamic range in seven patients using multielectrode cochlear implants. The range between threshold and saturation level of the amplitude growth function usually either encompassed or fell between the preferred and uncomfortable listening levels. Implications of these findings for the initial mapping of electrodes in young children are discussed.

Abnormalities of the acoustic reflex in multiple sclerosis

Acoustic reflect morphology was examined in 122 patients with a diagnosis of definite multiple sclerosis. Abnormality in some dimension of acoustic reflex morphology was observed in 75 percent of the study population. The most commonly observed abnormality was an alteration in one or more of the three relative amplitude indices (afferent, efferent, or central pathway index). Other abnormalities included delayed onset latency, delayed offset latency, reduction in absolute amplitude, and threshold elevation.

Problems in the Clinical Measurement of Acoustic Reflex Latency

Two problems in the clinical measurement of acoustic reflex latency are discussed. First, the rise characteristic of the reflex is affected by the frequency of the eliciting signal. Due to the closed ipsilateral feedback loop system the reflex rises more rapidly at low frequencies than at high frequencies. Second, the temporal characteristic of the measurement apparatus may influence the apparent morphology of the reflex at low frequencies.

Interaction of age and intersignal interval on acoustic reflex amplitude.

We studied the effect of intersignal interval (ISI) on the averaged acoustic reflex in nine young and nine elderly subjects. Over the range of ISIs from 1.5 to 9 sec, there was an interaction between ISI and age group, but the effect was unique to reflex mode. Results emphasize the importance of measuring both crossed and uncrossed reflex waveforms, in the study of aging, and of controlling the ISI in order to avoid overestimation of aging effects.

Suprathreshold abnormalities of the stapedius reflex in acoustic tumor: a series of case reports

Suprathreshold morphologic characteristics of the acoustic stapedius reflex are reported for five subjects with acoustic tumor. Results support the hypothesis that changes in Suprathreshold morphology may be more sensitive to acoustic tumor than conventional reflex threshold and decay measures. Both the afferent relative amplitude index (Al) and measures of sequential variability of individual waveforms appear to be especially promising.