"I said simPle, not symBol!"Is clear speech tailored to the listener's feedback

Abstract

This study investigates variation in the production of French stop consonants in two situations of speech clarity enhancement – when addressing an interlocutor experiencing listening difficulties in a disrupted communication environment (clear speech), and when correcting specific listener misunderstandings (corrected speech). Of interest is whether speech modifications are similar in both situations, or if adjustments during correction specifically address listeners' errors.

Twelve native French speakers interacted with the experimenter in a gaming task, first in conversational speech ('Conv') under normal conditions, then in clear speech prompted by apparent listening difficulties from the interlocutor ('Clear'). In the disrupted situation, some words were misunderstood by the listener (errors in either voicing or articulation place of stop consonants), resulting in additional corrections by the speaker ('Clear+Corr').

Significant changes in the timing and spectral cues of stop consonants (closure duration, Voice Onset Time, burst spectrum) were observed in both clear and corrected speech, improving distinctions between voiced and voiceless stops and articulation places. Additionally, clear speech prompted by listening difficulties showed global modifications (overall increased intensity, longer syllable duration, hyper-articulated vowels). Conversely, corrected speech focused solely on segmental modifications, with burst spectrum variations significantly influenced by listener feedback, emphasizing the distinction between the speaker's intended segment and the misunderstood one.

The results suggest that both situations of speech clarity enhancement involve different strategies, with speech correction relying on real-time perception of the listener's feedback to specifically address perceptual errors.