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Biomedical subjects

M R Chial

Publications and source records attributed to M R Chial.

5 recordsLinked to original sources

Word recognition performance in various background competitors.

Word recognition performance was measured for 18 normal-hearing subjects using the female talker version of the Northwestern University Auditory Test No. 6 (NU-6) in the presence of three background competitors: (1) a meaningful multitalker competing message consisting of three male and three female talkers (forward multitalker competing message [FCM]), (2) the same multitalker competing message recorded in reverse to eliminate semantic content (backward multitalker competing message [BCM]), and (3) an amplitude-modulated speech-spectrum noise (SSN) having the same long-term average spectrum and amplitude fluctuations as the meaningful multitalker competing message. The meaningful competitor had a significantly more deleterious effect on recognition performance compared to performance for the two nonmeaningful competitors. Furthermore, the nonmeaningful speech competitor produced a significantly greater degradation in performance than that for the SSN.

Adolescent↗

Magnitude estimation of degraded speech quality by normal- and impaired-hearing listeners.

Speech quality magnitude estimates (SQME's) were obtained from 12 sensorineurally impaired-hearing listeners on connected speech samples degraded by changing low-pass filter cutoff frequency, high-pass filter cutoff frequency, or percent total harmonic distortion (THD) by linear rectification. Log SQME's varied linearly with log bandwidth for filtered signals and with log percent undegraded (100-% THD) for linearly rectified signals. Significant variations were found among the slopes of the log-log functions for degradation modes and group-by-degradation mode interactions. Slope differences appeared to represent differential sensitivity of the listeners to changes in mode and degree of degradation. The findings are sufficiently encouraging to suggest that direct scaling procedures be employed in future studies of the evaluation of communication systems and the perception of complex signals.

Adolescent↗

Cost-benefit analysis of two decision criteria for spondee threshold measurements.

Normal-hearing subjects were tested and retested using two spondee threshold criteria: a strict 50 percent correct rule and a 50 percent or 75 percent correct (or both) rule. The 50 percent criterion produced lower thresholds at the cost of poorer test-retest reliability and longer test durations. Both decision rules gave lower threshold SPL values and required less testing time during the second trial. A proposed benefit-cost ratio model indicated that the 50 percent or 75 percent (or both) decision rule gives a better return on the investment of clinical effort.

Adult↗