Psychometric Function Characteristics of Time- Compressed Persian Words

Mohammadsaleh  Moosapour Bardsiri; Mohammad Ebrahim Mahdavi

doi:10.18502/avr.v31i3.9867

Mohammadsaleh Moosapour Bardsiri Department of Audiology, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mohammad Ebrahim Mahdavi Department of Audiology, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran

DOI: https://doi.org/10.18502/avr.v31i3.9867

Abstract

Background and Aim: The psychometric function characteristics (e.g. threshold and slope) of the time-compressed words have not been investigated in previous studies to compile psychometrically homogeneous word lists. Therefore, this study aimed to investigate psychometric function characteristics of monosyllabic time-compressed Persian words to develop psychometrically equivalent time-compressed word lists.

Methods: Two hundred most common monosyllabic words in Persian language were time- compressed at a rate of 40%-85% and presented to 21 participants with normal hearing at a fixed intensity level. The threshold and slope of the psychometric function for all words were determined using the logistic regression. The compression ratio (CR) for 5%-95% correct recognition was predicted based on the psychometric function fitted to the measured correct recognition score.

Results: Mean CR 50% of the words was in a range of 53%-78%. The mean CR 50% and slope were not significantly different between consonant-vowel-consonant and consonant- vowel-consonant-consonant words. The predicted CR for 5%-95% correct recognition varied from 61.5% to 88.4%. The final result was two 50-word lists of monosyllabic words with the same mean threshold and slope.

Conclusion: Persian time-compressed monosyllabic words have different CR 50% and slope that may interact with their intelligibility.

Keywords: Time compression; intelligibility; psychometric function; Persian monosyllabic words