The sound of Passion and Indifference

Extending affective speech communication research in the context of authentic, spontaneous utterances, the present study investigates two signals of affect defined by extreme levels of physiological arousal-Passion and Indifference. Exemplars were mined from podcasts conducted in informal, unstructured contexts to examine communication at extreme levels of perceived hyper- and hypo-arousal. Utterances from twenty native speakers of Canadian/American English were submitted for perceptual validation for judgments of affective meaning (Passion, Indifference, or Neutrality) and level of arousal (“Not At All” to “Very Much”). Arousal ratings, acoustic patterns, and linguistic cues (affect/emotion words and expletives) were analyzed. In comparison to neutral utterances, Passion was communicated with the highest maximum pitch and pitch range, and highest maximum and mean amplitude, while Indifference was communicated via decreases in these measures in comparison to neutral affect. Interestingly, Passion and Neutrality were expressed with comparable absolute ranges of amplitude, while the minimum amplitudes of both Passion and Indifference were greater than those of Neutral expressions. Linguistically, Indifference was marked by significantly greater use of explicit expressions of affect (e.g. I don't care…), suggesting a linguistic encoding preference in this context. Passion was expressed with greater use of expletives; yet, their presence was not necessary to facilitate perception of a speaker's level of arousal. These findings shed new light upon the paralinguistic and linguistic features of spontaneous expressions at the extremes of the arousal continuum, highlighting key distinctions between Indifference and Neutrality with implications for vocal communication research in healthy and clinical populations.