Analyzing speech rate entrainment and its relation to therapist empathy in drug addiction counseling

A key quality index in drug addiction counseling such as Motivational Interviewing is the degree of therapist’s empathy towards the client. Empathy ratings are meant to evaluate the therapist’s understanding of the patient’s feelings, through their sensitivity and care of response. Empathy is also associated with the manifestation of behavioral entrainment in the interaction. In this paper, we compute a measure of entrainment in speech rate during dyadic interactions, and investigate its relation to perceived empathy. We show that the averaged absolute difference of turn-level speech rates between the therapist and the patient correlates with the ratings of therapist empathy. We also present the correlation of empathy to the statistics of speech and silence durations. Finally we show that in the task of automatically predicting high or low empathy, speech rate cues provide complementary information to previously proposed prosodic cues. These findings suggest speech rate as an important behavioral cue that is modulated by entrainment and contributes to empathy modeling.