Speech rate adjustment of adults during conversation.

Purpose: Speech rate convergence has been reported previously as a phenomenon in which one's speech rate is influenced by his/her partner's speech rate. This phenomenon has been demonstrated in artificial settings, and to some extent, in mother-child interactions. The purpose of this study was to explore speech rate adjustment in a quasi-natural adult-adult conversation.

Methods: An A-B-A-B paradigm was used, in which ten adults conversed on a given topic with two experimenters. Speech rates of both communication partners were measured.

Results: Participants significantly reduced their speech rate, in response to the experimenters' reduction in speech rate. However, the participants' reduction in speech rate was significantly smaller than the experimenters' reduction in speech rate. In addition, during the controlled slow speech rate, the participants' speech rate correlated negatively with that of the experimenters'.

Conclusion: Results suggest that speech rate convergence is a non-linear phenomenon, and may be affected by various linguistic as well as communicational factors. From a clinical perspective, the results support the use of the modeling strategy in speech therapy, as a means to facilitate a reduction in clients' speech rate.