Affect in the human voice

Chapter 9 endnote 25, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

We all criticize our kids now and then, but try to make your feedback specific. [...] Your tone of voice matters too, since it easily communicates your affect and directly impacts the child’s nervous system.

Five month old infants perceive affect in a human voice, even when they have difficulty doing so in human faces.[1][2][3][4] Even when both are available, vocal cues are more potent.[5] A child’s nervous system may respond to the rhythm, intonation, and loudness of a voice directly, without any learning at all.

You communicate affect through vocal prosody. You don’t even need words.  The other person’s nervous system will represent these changes, which causes an affective change in them. This idea, known as the "affect induction hypothesis,"[6][7][8][9] proposes that sounds (baby cries, sirens, laughs, thunderstorm booms, etc.) have a direct effect on the nervous system of the listener without much conceptualization. This hypothesis originally developed to explain how non-human primates communicate via vocalizations; the function of vocal cues is not necessarily to express anything about the internal state of the speaker but to change the arousal level of the listener.

The affect induction hypothesis proposes that vocal acoustics carry information about a speaker's arousal level, which in turn influences arousal of listener. So affective information is not "encoded" and "decoded" but transferred. This is similar to Hatfield, Cacioppo, & Rapson (1992)'s idea of primitive "emotional contagion" (although the use of the word "emotion" is misplaced here).[10]

Notes on the Notes

  1. Fernald, Anne. 1993. "Approval and Disapproval: Infant Responsiveness to Vocal Affect in Familiar and Unfamiliar Languages." Child Development 64 (3): 657-674
  2. Caron, Albert J., Rose F. Caron, and Darla J. MacLean. 1988. "Infant discrimination of naturalistic emotional expressions: The role of face and voice." Child Development 59 (3): 604-616.
  3. Perceiving affect in faces presented at about 7 months of age, vs. 5 months for perceiving affect in voices, but infants as young as 4 months can perceive affect from combined cues; see Flom, Ross, and Lorraine E. Bahrick. 2007. "The Development of Infant Discrimination of Affect in Multimodal and Unimodal Stimulation: The Role of Intersensory Redundancy." Developmental Psychology, 43 (1) 238-252.
  4. Young infants appear to be born with the ability to make sounds with acoustics that indicate affect, but their ability to string them together and order them into sequences appears to be learned, as indicated by comparing the vocal acoustics made by normally hearing and hearing-impaired infants. See Scheiner, Elisabeth, Kurt Hammerschmidt, Uwe Jürgens, and Petra Zwirner. 2006. "Vocal expression of emotions in normally hearing and hearing-impaired infants." Journal of Voice 20 (4): 585-604.
  5. Vaish, Amrisha, and Tricia Striano. 2004. "Is visual reference necessary? Contributions of facial versus vocal cues in 12‐month‐olds’ social referencing behavior." Developmental Science 7 (3): 261-269.
  6. Owren, Michael J., and Drew Rendall. 1997. "An affect-conditioning model of nonhuman primate vocal signaling." In Perspectives in Ethology, Volume 12, Communication, edited by Donald H. Owings, Michael D. Beecher, and Nicholas S. Thompson, 299-346. New York: Plenum Press.
  7. Owren, Michael J., and Drew Rendall. 2001. "Sound on the rebound: bringing form and function back to the forefront in understanding nonhuman primate vocal signaling." Evolutionary Anthropology: Issues, News, and Reviews 10 (2): 58-71.
  8. Rendall, Drew and Michael J. Owren. 2002 "Animal vocal communication: Say what?" In The Cognitive Animal: Empirical and Theoretical Perspectives on Animal Cognition, edited by Marc Bekoff, Colin Allen, and Gordon M. Burghardt, 307-313. Cambridge, MA: MIT Press.
  9. Bachorowski, Jo-Anne, and Michael J. Owren. 2008. "Vocal expressions of emotion." In Handbook of Emotions, 3rd edition, edited by Michael Lewis, Jeannette M. Haviland-Jones, and Lisa Feldman Barrett, 628–642. New York: Guilford Press.
  10. Hatfield, E., Cacioppo, J. T., and Rapson, R. L. 1992. "Primitive emotional contagion." In Review of Personality and Social Psychology: Emotion and Social Behavior, edited by M. S. Clark, 151–177. Newbury Park, CA: Sage.