Tenseness relaxed by vocalizing, illustrated by horses (Equus caballus) whinnying.

This research looked at how animal calls, specifically horse whinnies, correlate with changes in their physiological arousal state, with observations suggesting that vocalizing could help animals relax when excited.

Introduction

• The study focused on investigating animal calls which are typically considered an indicator of a sudden change in physiological arousal state. However, this study aimed to provide evidence of corresponding internal physiological changes related to these vocalizations.

Methodology

• 15 stallions were involved in the experiment. Each was fitted with a heart rate monitor to track physiological responses.
• To induce arousal, a mare was shown to each stallion at a distance that prevented physical contact. The presence of the mare was expected to increase the arousal of the stallions.

Findings

• Researchers noted an increase in the stallions’ heart rates just before they whinnied, hence validating the assumption that an increased arousal is associated with producing their vocal calls.
• Interestingly, while vocalizing their calls (whinnying), the stallions’ heart rates were observed to return to their baseline rates. This suggests that the act of calling itself could have a relaxing effect on the animals, helping lower heightened arousal.

Conclusion

• The study demonstrated a possible sustainable link between the vocalizations of an animal and its physiological state, indicating that sudden changes in an animal’s arousal state could be associated with vocal calls.
• This finding opens up new potential pathways for non-invasive research related to the self-regulation of emotional state through vocal production, not only in animals but also potentially relevant to human research.