Speaker
Description
When conducting conversations in adverse acoustic conditions (e.g., in background noise), talkers tend to alter their speech production to increase speech clarity for their interlocutors. Compared to casual speech, such “clear speech” has been reported to facilitate speech intelligibility in challenging listening situations, but this evidence has been obtained through passive listening tests where listeners attended to stimuli that did not meet the requirements of standard speech-intelligibility test materials. Furthermore, the physical and cognitive effort required by the talker to produce clear speech, as well as the cognitive listening effort required by the listener to attend it, are currently underexplored. This study introduces a novel conversation-based testing paradigm combining measures of speech intelligibility, speaking effort and listening effort. Pairs of interlocutors conducted a conversation elicited through a visual task, during which the participants were alternatingly required to read sentences from standard speech-intelligibility test material and their interlocutor had to repeat them, allowing to extract a measure of speech intelligibility from a conversational setting. During the conversation, a set of voice features were measured to quantify the physical component of speaking effort, while pupil dilation measured during speaking and listening activity provided proxy measures of cognitive speaking and listening effort, respectively. Through separate acoustic environments, an independent manipulation of noise exposure allowed to disentangle how speaking and listening effort were affected by the talker and listener acoustic condition. The experimental method will be presented and discussed in terms of the outcome measures of speech intelligibility, voice features, and pupil dilation.