The link between auditory salience and emotion intensity

ABSTRACT

To ensure that listeners pay attention and do not habituate, emotionally intense vocalizations may be under evolutionary pressure to exploit processing biases in the auditory system by maximising their bottom-up salience. This “salience code” hypothesis was tested using 128 human nonverbal vocalizations representing eight emotions: amusement, anger, disgust, effort, fear, pain, pleasure, and sadness. As expected, within each emotion category salience ratings derived from pairwise comparisons strongly correlated with perceived emotion intensity. For example, while laughs as a class were less salient than screams of fear, salience scores almost perfectly explained the perceived intensity of both amusement and fear considered separately. Validating self-rated salience evaluations, high- vs. low-salience sounds caused 25% more recall errors in a short-term memory task, whereas emotion intensity had no independent effect on recall errors. Furthermore, the acoustic characteristics of salient vocalizations were similar to those previously described for non-emotional sounds (greater duration and intensity, high pitch, bright timbre, rapid modulations, and variable spectral characteristics), confirming that vocalizations were not salient merely because of their emotional content. The acoustic code in nonverbal communication is thus aligned with sensory biases, offering a general explanation for some non-arbitrary properties of human and animal high-arousal vocalizations.

KEYWORDS:

• Emotion
• arousal
• salience
• sensory bias
• nonverbal vocalizations

Acknowledgments

I would like to thank Tomas Persson and Peter Gärdenfors for their comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All materials for running the experiments (HTML, audio stimuli, etc.), datasets of responses, and scripts for statistical analysis can be downloaded from http://cogsci.se/publications.html.

Additional information

Funding

This work was supported by Elisabeth Rausing's memorial fund, grant RFh2019-0120.