The voice of trustworthiness

Many studies suggest that women's voices are affected by menstrual cycle. However, these studies focused on vocal attractiveness only (e.g. Pipitone & Gallup, 2008). In the present study we aimed at investigating whether the menstrual cycle also affects the perceived trustworthiness of a speaker and to identify physical acoustic characteristics that make female voices sound trustworthy. The voice of 20 female speakers was recorded around ovulation and in the luteal phase. Ovulation was determined by means of ovulation tests and the cycle phases were confirmed by means of hormone assays. From each speaker, voice recordings of both cycle phases were paired. An independent sample of participants were asked to pick the voice sample that sounded more trustworthy of each pair (two-alternative forced choice). Participants were allowed to replay the stimuli as often as they wished before responding. Stimuli were also rated for attractiveness. We used three sentences that suggested a mating context and three sentences of neutral content because context may play a role. Preliminary data suggest that voice samples recorded around ovulation are perceived as being more trustworthy than voices recorded in the luteal phase.