Effects of speaking rate changes on native and nonnative speech production

Area of Science:

• Phonetics and phonology
• Second language acquisition
• Speech production

Background:

• Voice onset time (VOT) is a key feature distinguishing speech sounds.
• Speaking rate can influence phonetic realizations, including VOT.
• Previous research indicates native language influences VOT production in second language learners.

Purpose of the Study:

• To investigate how speaking rate affects voice onset time (VOT) for English /p/ in native Spanish speakers with varying English proficiency.
• To compare the VOT production of native Spanish speakers to native English speakers across different speaking rates.
• To explore evidence for the establishment of phonetic categories for English /p/ in second language learners.

Main Methods:

• Monolingual English speakers (n=20) and native Spanish speakers (n=40) with varying English proficiency produced English /p/ at normal and fast speaking rates.
• Voice onset time (VOT) and durational measures (vowel, phrase) were analyzed.
• Production data was compared between native English speakers and native Spanish speakers across speaking rates.

Main Results:

• Native English speakers exhibited a typical rate effect on VOT.
• Proficient native Spanish speakers showed an English-like rate effect on VOT and used fewer short-lag stops.
• Nonproficient native Spanish speakers used more short-lag stops and did not show a significant speaking rate effect on VOT, but did show effects on vowel and phrase duration.

Conclusions:

• Proficiency in English correlates with native Spanish speakers' ability to modify VOT according to speaking rate.
• Native Spanish speakers who closely matched native English VOT patterns and rate effects may have established a phonetic category for English /p/.
• Speaking rate influences phonetic production differently based on second language proficiency, highlighting the dynamic nature of phonetic category acquisition.