Do Sound Segments Contribute to Sounding Charismatic? Evidence from a Case Study of Steve Jobs' and Mark Zuckerberg's Vowel Spaces

Abstract

The paper presents a case study of two popular US American CEOs. It compares the acoustic vowel space sizes of the more charismatic speaker Steve Jobs and those of the less charismatic speaker Mark Zuckerberg, as part of an initial acoustic step to examine a traditional claim of rhetoric that clearer speech makes a speaker sound more charismatic. Analysing about 2,000 long and short vowel tokens from representative keynote speech excerpts of the two speakers shows that Jobs’ vowel space is, across various segmental and prosodic context factors, significantly larger than that of Zuckerberg, whose vowel space is strongly reduced particularly when addressing investors. The differences in vowel-space size are consistent with the claim of rhetoric that a clear articulation is a key characteristic of a charismatic speaker. The discussion of the results describes further experimental steps required to back up the link between clear pronunciation and speaker charisma.

Computer-Generated Speaker Charisma and Its Effects on Human Actions in a Car-Navigation System Experiment - or How Steve Jobs’ Tone of Voice Can Take You Anywhere

“…The less charismatic tone-of-voice profile was derived from speeches by Mark Zuckerberg, who, unlike Jobs, is as a less charismatic and convincing speaker. These assumptions about the two speakers have already been confirmed for their acoustic profiles by previous perception studies with depersonalized, lowpass-filtered speech (Niebuhr et al 2018a;Niebuhr & Gonzalez 2019).…”

What Makes Business Speakers Sound Charismatic?

“…In fact, MZ's speaking rate is so high that it caused a lot of extreme segmental reductions. As is reported in Niebuhr and Gonzalez (2019) and Niebuhr (2020), MZ's vowel space is significantly smaller, i.e. his vowels are all more centralized and phonetically less distinct from one another than those of SJ.…”

“…In a similar vein, but a few years earlier, Rosenberg and Hirschberg (2009) already called for an empirical definition of charismatic speech and, then, provided a first answer to their call by projecting ratings of perceived charisma attributes onto acoustic-prosodic features of speakers. This empirical foundation was further supported and enriched by similar studies of Biadsy et al (2008), Signorello et al (2012Signorello et al ( , 2013, Niebuhr, Voße, and Brem (2016), Niebuhr and Fischer (2019), Niebuhr and Skarnitzl (2019), Niebuhr and Gonzalez (2019), Hiroyuki and Rathcke (2016), Novák-Tót, Niebuhr, and Chen (2017), Bosker (2017), Strangert and Gustafson (2008), D 'Errico et al (2013), Berger, Niebuhr and Peters (2017),…”

Myth busted? Challenging what we think we know about charismatic speech

“…Steve Jobs, who is perceived to be more charismatic than Mark Zuckerberg both by representatives of the media and listeners in a controlled perception experiment (Niebuhr et al, 2018a), performs significantly better than Zuckerberg in acoustically distinguishing his voiced and voiceless stop consonants (/p t k/ vs /b d ɡ/) as well as the different vowel qualities of American English. The acoustic vowel space that Jobs uses in his speech is at least 32.7% larger than that of Zuckerberg (Niebuhr and Gonzalez, 2019). Furthermore, Jobs' speech includes 28.3% fewer instances of post-lexical assimilation of alveolar consonants (/t d n/) to either bilabial or velar plac-es of articulation than Zuckerberg's speech (Niebuhr et al, 2018a).…”