How rhythm metrics are linked to produced and perceived speaker charisma

Based on a medium-sized sample of English investor-oriented business-idea presentations (so-called “investor pitches”), the present paper investigates the links between speech rhythm and perceived speaker charisma. Eight trained public speakers are recorded while performing the same investor pitch twice, once in an emotionally-neutral matter-of-fact fashion and once charismatically, i.e. in an expressive, committed onstage presentation style. The recorded presentations were rated by 21 listeners for their degree of perceived speaker charisma - and additionally acoustically analyzed in terms of established duration-based rhythm measures such as Θ, Δ, and PVI. We find significant rhythmic differences between the matter-of-fact and charismatic presentation performances and, in conjunction with the perception results, we show that consonantal rhythmic elements play a bigger role in the perception than in the production of a rhythmic charisma, and that especially the duration variation of larger rhythm elements correlates positively and gender-independently with charisma ratings. The findings are discussed in light of previous studies with their practical implications.