Presentation method as air- and bone-conducted speech for delayed auditory feedback

Abstract

Speakers perceive their own voices as “auditory feedback” during speech production. Effects of delayed auditory feedback (DAF) on their speaking styles have been investigated to clarify relationships between speech production and perception. It has been previously investigated whether DAF as not only air-conducted (AC) but also bone-conducted (BC) speech affects speakers’ speaking styles. However, existence of speakers’ own natural voice via bone-conduction could not be ignored. This study investigates the speaking styles under DAF as AC and BC speech in presence of masker, for clarifying the effects of only delayed stimuli as AC and BC speech. Speech duration and the number of dysfluent episodes under delay conditions were measured to quantify the effect of delayed stimuli on the speaking styles. As a result, under noiseless and AC masker conditions, longer speech duration and more dysfluencies were observed under DAF as BC speech than that as AC speech. In contrast, under BC masker condition, opposite trends were observed. Speakers’ introspection suggested that their own natural voices were masked by AC masker better than BC masker. These results indicated that the use of AC masker is effective for masking speakers’ own natural voice during DAF as AC and BC speech.