American English adults’ perception of Spanish-accented conversational and clear speech.

Abstract

Clear speech, an intelligibility-enhancing manner of speech production, has been shown to increase the transmission of information to various listener groups when uttered in the speaker’s native language. When clear speech is used in a non-native language, it is not evident whether this mode will also improve intelligibility. The present study examined the accuracy with which adult monolingual native American English (AE) listeners identified Spanish-accented vowels produced in conversational and clear speech modes. Consonant-vowel-consonant (CVC) words were presented in the carrier sentence “Touch the CVC please,” containing the AE vowels /æ, ʌ, ɑ, ε, i, ɪ/. The sentences were produced by a native speaker of AE and by a native speaker of Spanish judged as moderately accented by the AE listeners. Five pairs of photographs (cap-cup, map-mop, nut-knot; ship-sheep, pot-pet), representing the vowel pairs /æ-ʌ/, /æ-ɑ/, /ʌ-ɑ/, /ɪ-i/, /ɑ-ε/ were presented visually on a touch screen in a two-alternative forced choice paradigm. Listeners had the greatest difficulty with the /ɪ-i/ and /ʌ-ɑ/ contrasts. Clear speech mode was not as effective for non-native speech as it has been shown for native speech. Implications are considered for social and clinical settings in which a mismatch in language backgrounds is present.