How’s my kitty? Acoustic parameters of cat-directed speech in human-cat interactions

In Western cultures, humans tend to use a specific kind of speech when talking to their pets, characterised, from an acoustical point of view, by elevated pitch and greater pitch modulation. Pet-directed speech (PDS), which has been mainly studied in dogs, shares some acoustic features with infant-directed speech (IDS), used when talking to young children. The purpose of this study was to test the hypothesis that adult humans also modify charac-teristics of their voice when talking to a cat. We compared acoustic parameters of speech directed to cats (CDS) and speech directed to adult humans (ADS). In a first experiment, we compared ADS and CDS utterances of male and female participants, addressing cats through video recordings, under controlled laboratory conditions. Both men and women used a higher pitch (mean fundamental frequency, or mean F0) in CDS vs. ADS. The second experiment was conducted under conditions allowing direct cat-human interactions, in a cohort of women. Once again, mean F0 was significantly higher in CDS vs. ADS. Overall, these data confirm our hypothesis that humans change the way they speak when addressing a cat, mainly by increasing the pitch of their voice. Further research is needed to fully investigate specificities of this speech.