A comparison was made between speech recognition performance in conditions of quiet and babble (Speech Perception in Noise Test) and items from a self-assessment scale concerned with communication ability in quiet and noise (Understanding Speech section of Hearing Performance Inventory). Performance on both the speech recognition and self-assessment tests differentiated between normal listeners and individuals with mild-to-moderate sensorineural hearing loss. For the hearing-impaired group, correlations between speech recognition scores and ratings on the self-assessment items were poor, suggesting that performance measured with these tests have only a weak relationship.

Adult↗

PubMedDate not supplied

Nonacoustic stimulation of the middle ear muscle reflex.

The purpose of these experiments was to determine the incidence of the middle ear reflex in response to several nonacoustic (tactile and air jet) stimuli among subjects with normal hearing who had an acoustic reflex and selected patients with severe hearing loss. The results demonstrate that the incidence of response to tactile stimulation increases as the facial area stimulated approaches the auricle. The response to an air jet stimulus directed toward the eye is high; however, the clinical utility of the air jet may be limited because it often results in a startle reaction and head movement, and the response appears to fatigue easily. In normal listeners the response to auricular air jet stimulation probably results from both acoustic and tactile stimulation. The presence of a reflex to tactile stimulation, together with normal tympanometry constitutes strong evidence of a normal middle ear; but the absence of a reflex to acoustic or tactile stimuli still leads to an ambiguous determination of potential stapedial muscle function.

Acoustic Stimulation↗

PubMedDate not supplied

Properties of acoustic reflex adaptation.

The dynamic behavior of the acoustic reflex to continuous sinusoidal stimuli was investigated. The major purpose was to determine the temporal characteristics of reflex adaptation as frequency (0.5, 1.0, 2.0, 3.0, 4.0 kHz) and suprathreshold level (6, +12, +18 dB re reflex threshold) were systematically varied. Repeated measurements were made with an impedance bridge on six normal listeners. Both relative and absolute impedance changes were analyzed. The results revealed large intersubject variability. Four general conclusions were reached regarding the effect of stimulus frequency and suprathreshold level on adaptation: 1) as the stimulus frequency increases, the rate of adaptation increases; 2) the adaptation curves appear to form distinct groups, at the low frequencies adaptation rates are significantly slower than those at 2.0 kHz and above; 3) the onset of adaptation occurs at an earlier time for the higher frequencies; and 4) the rate of adaptation was found to be independent of suprathreshold level. The changes in adaptation with frequency of the stimulus may be expressed by an equation involving inter-related time constants for the growth and adaptation portions of the reflex curve in accordance with a descriptive model suggested by Tietze.

Acoustic Stimulation↗

PubMedDate not supplied

Evaluation of the speech perception in noise (SPIN) test.

Several investigations were perfomed with normal hearing subjects to determine the effects of presentation level and signal-to-babble ratio on the speech perception in noise (SPIN) test. The SPIN test contains sentences that simulate a range of contextual situations encountered in everyday speech communication. Findings from several representative patients with sensorineural hearing loss demonstrate the possible clinical utility of the test to measure the effects of context on speech discrimination.

Acoustic Stimulation↗