Clarifications in spontaneous speech under three different adverse communicative situations.
Rachel Baker, Valerie L. Hazan · The Journal of the Acoustical Society of America · 2010
Difficult communicative situations requiring clear speech are common. This study investigated whether (a) clear speech elicited by instructing talkers to read sentences clearly reflects clarifications made by talkers in spontaneous speech with communicative intent and (b) talkers modulate their clear speech according to the type of adversity under which communication takes place. Casual and clear speech from 40 Southern British English talkers was elicited in dialogues recorded while two talkers engaged in “spot the difference” picture tasks, based on the Diapix task of Bradlow and collaborators. Three types of “communication barrier” were used to elicit clear speech: in the VOC condition, one talker heard the other via a three-channel vocoder; in the NOISE condition, one person heard the other with simultaneous babble noise; in the L2 condition one talker was a low-proficiency non-native speaker. Read clear speech showed more extreme changes in median F0, F0 range and speaking rate than spontaneous clear speech. Greater changes were made to speaking rate and vowel space in the VOC than the L2 condition, while greater changes in F0 and mean energy were made in the NOISE than the VOC condition, suggesting that talkers clarify their speech according to listeners’ needs. [Work funded by ESRC project no. RES-062-23-0681.]