Speakers' vocal expression of sexual orientation depends on experimenter gender

Since the early days of (phonetic) convergence research, one of the main questions is which individuals are more likely to adapt their speech to others. Especially differences between women and men have been researched with a high intensity. Using a differential approach as well, we complement the existing literature by focusing on another gender-related characteristic, namely sexual orientation. The present study aims to investigate whether and how women differing in sexual orientation vary in their speaking behavior, especially mean fundamental frequency (f0), in the presence of a female vs. male experimenter. Lesbian (n = 19) and straight female speakers (n = 18) engaged in two interactions each: First, they either engaged with a female or male experimenter, and second with the other-gender experimenter (counter-balanced and random assignment to conditions). For each interaction, recordings of read and spontaneous speech were collected. Analyses of read speech demonstrated mirroring of the first experimenter's mean f0 which persisted even in the presence of the second experimenter. In spontaneous speech, this order effect interacted with exclusiveness of sexual orientation: Mirroring was found for participants who reported being exclusively lesbian/straight, not for those who reported being mainly lesbian/ straight. We discuss implications for studies on convergence and research practice in general.