Assessing vowel effects on voice quality, and voice quality effects on the respiratory system

Abstract

This study assesses (a) effects of vowel height and tense-lax status on the laryngeal closed quotient (CQ) and (b) whether respiratory volume changes vary with differences in CQ. German speakers produced words containing eight different vowels in normal and loud conditions. The only significant vowel effect was found for the /a:-a/ pair, with lower CQ in /a/ at normal intensity. There was an insignificant trend for lower CQ to be associated with more negative thoracic slopes. The CQ difference for the /a:-a/ contrast, which relies more on duration than other tense-lax pairs in German, requires further study.