Production of Vowels by Electrolaryngeal Speakers Using Clear Speech

Abstract

Background/Aims: This study examined the effect of clear speech on vowel productions by electrolaryngeal speakers. Method: Ten electrolaryngeal speakers produced eighteen words containing /i/, /ɪ/, /ɛ/, /æ/, /eɪ/, and /oʊ/ using habitual speech and clear speech. Twelve listeners transcribed 360 words, and a total of 4,320 vowel stimuli across speaking conditions, speakers, and listeners were analyzed. Analyses included listeners’ identifications of vowels, vowel duration, and vowel formant relationships. Results: No significant effect of speaking condition was found on vowel identification. Specifically, 85.4% of the vowels were identified in habitual speech, and 82.7% of the vowels were identified in clear speech. However, clear speech was found to have a significant effect on vowel durations. The mean vowel duration in the 17 consonant-vowel-consonant words was 333 ms in habitual speech and 354 ms in clear speech. The mean vowel duration in the single consonant-vowel words was 551 ms in habitual speech and 629 ms in clear speech. Conclusion: Finding suggests that, although clear speech facilitates longer vowel durations, electrolaryngeal speakers may not gain a clear speech benefit relative to listeners’ vowel identifications.