As group size increases, individuals modify their vocal features to signal cooperation while remaining recognizable

Area of Science:

• Speech communication
• Acoustic phonetics
• Social psychology

Background:

• Human cooperation relies on vocal accommodation, where voices become more similar.
• Maintaining vocal individuality is crucial when recognizability is prioritized over alignment.
• Animal communication suggests larger social groups foster greater vocal individuality.

Purpose of the Study:

• To investigate how group size influences vocal accommodation and the balance between cooperation and individuality.
• To determine if speakers adapt their vocal features to maintain recognizability in varying group sizes.

Main Methods:

• An interactive online game assessed vocal accommodation in groups of 3 and 5 players.
• Acoustic features (harmonicity, jitter, F0, formant dispersion, duration) were analyzed.
• Principal Component Analysis reduced acoustic data to identify group size effects on vocal convergence.

Main Results:

• Accommodation was selective in larger groups; speakers converged on some features while maintaining others.
• No significant group size effect was found for voice quality measures (PC1).
• Reduced inter-speaker differences (PC2), driven by F0 and duration, indicated convergence in larger groups, often asymmetrical.

Conclusions:

• Speakers strategically balance cooperation and individuality based on group size and recognizability demands.
• Vocal accommodation is not uniform but selective, adapting to social contexts.
• Recognizability needs significantly shape how individuals accommodate their voices in group settings.