Encoding emotions in speech with the size code — A perceptual investigation
Suthathip Chuenwattanapranithi (Corresponding author)
Department of Computer Engineering, King Mongkut's University of Technology Thonburi,
Bangkok 10140, Thailand
Email: chuenwattana@yahoo.com
Yi Xu
Department of Speech, Hearing and Phonetic Sciences, University College London, Chandler
House, 2 Wakefield Street, London WC1N 1PF, U.K.
Email: yi.xu@ucl.ac.uk
Bundit Thipakorn
Songrit Maneewongvatana
Department of Computer Engineering, King Mongkut's University of Technology Thonburi,
Bangkok 10140, Thailand
Running Title: Encoding emotions in speech with the size code
Suthathip Chuenwattanapranithi (Corresponding author)
Department of Computer Engineering, King Mongkut's University of Technology Thonburi,
Bangkok 10140, Thailand
Email: chuenwattana@yahoo.com
Yi Xu
Department of Speech, Hearing and Phonetic Sciences, University College London, Chandler
House, 2 Wakefield Street, London WC1N 1PF, U.K.
Email: yi.xu@ucl.ac.uk
Bundit Thipakorn
Songrit Maneewongvatana
Department of Computer Engineering, King Mongkut's University of Technology Thonburi,
Bangkok 10140, Thailand
Running Title: Encoding emotions in speech with the size code
1
Abstract
Our current understanding of how emotions are expressed in speech is still very limited.
Part of the difficulty has been the lack of understanding of the underlying mechanisms. Here
we report the findings of a somewhat unconventional investigation of emotional speech.
Instead of looking for direct acoustic correlates of multiple emotions, we tested a specific
theory, the size code hypothesis of emotional speech, about two emotions — anger and
happiness. According to the hypothesis, anger and happiness are conveyed in speech by
exaggerating or understating the body size of the speaker. In two studies consisting of six
experiments, we synthesized vowels with a 3D articulatory synthesizer with parameter
manipulations derived from the size code hypothesis, and asked Thai listeners to judge the
body size and emotion of the speaker. Vowels synthesized with a longer vocal tract and lower
F0 were mostly heard as from a larger person if the length and F0 differences were stationary,
but from an angry person if the vocal tract was dynamically lengthened and F0 was
dynamically lowered. The opposite was true for the perception of small body size and
happiness. These results provide preliminary support for the size code hypothesis. They also
point to potential benefits of theory-driven investigations in emotion research.
Keywords: Emotional speech, Vocal emotion, Anger, Happiness, Size code,
Articulatory synthesis
http://www.phon.ucl.ac.uk/home/yi/yispapers/Chuenwattanapranithi_etAl_Author_version.pdf
Our current understanding of how emotions are expressed in speech is still very limited.
Part of the difficulty has been the lack of understanding of the underlying mechanisms. Here
we report the findings of a somewhat unconventional investigation of emotional speech.
Instead of looking for direct acoustic correlates of multiple emotions, we tested a specific
theory, the size code hypothesis of emotional speech, about two emotions — anger and
happiness. According to the hypothesis, anger and happiness are conveyed in speech by
exaggerating or understating the body size of the speaker. In two studies consisting of six
experiments, we synthesized vowels with a 3D articulatory synthesizer with parameter
manipulations derived from the size code hypothesis, and asked Thai listeners to judge the
body size and emotion of the speaker. Vowels synthesized with a longer vocal tract and lower
F0 were mostly heard as from a larger person if the length and F0 differences were stationary,
but from an angry person if the vocal tract was dynamically lengthened and F0 was
dynamically lowered. The opposite was true for the perception of small body size and
happiness. These results provide preliminary support for the size code hypothesis. They also
point to potential benefits of theory-driven investigations in emotion research.
Keywords: Emotional speech, Vocal emotion, Anger, Happiness, Size code,
Articulatory synthesis
http://www.phon.ucl.ac.uk/home/yi/yispapers/Chuenwattanapranithi_etAl_Author_version.pdf