Effects of Word Recognition Score as a Function of Consonant-to-Vowel Ratio (CVR) in Korean Non-sense Syllables

Abstract

Non-linear amplification may increase intensity of consonants through improvement of consonants-to-vowel ratio (CVR). In this study, we evaluated the effects of word recognition scores for nonsense consonant-vowel (CV) syllables as a function of CVR. Twenty adults (32 ears) with sensorineural hearing loss participated and five consonants (/s/, /tɕh/, /kh/, /th/, /ph/) and three vowels (/u/, /a/, /i/) were used in this study. CV syllables were recorded by male and female talkers and combined with speech noise at 5 different CVR (0, 3, 6, 9, 12 dB). Randomized list of 150 nonsense CV syllables was presented to the participants at the most comfortable level. As a results, no significant differences were observed between the male and the female talkers in nonsense syllables recognition at all CVR. However, results indicated that audibility of consonants improved when CVR increased up to 6 dB or more. Error analysis demonstrated that substitution errors were the most frequently made in word-initial position and vowels. These findings provide meaningful information about auditory rehabilitation for the Korean hearing impaired and also help audiologists to make an effective decision on the compression threshold, compression ratio, and attack and release time of non-linear hearing aids. KEY WORDS：Consonant·Consonant-to-vowel ratio (CVR)·Non-sense syllable·Vowel.