Musical or Mechanical? Which Type of Sound is More Effective in Social Robot Communication?

Effective communication is essential for successful human-robot interaction. Inspired by familiar robotic sound cues such as the "beep-boop" sounds of R2-D2, this study investigates whether mechanical or more musical sounds are perceived as more effective in conveying intentions. A survey-based study with 37 participants presented scenarios involving an on-campus social robot and four intentions: greeting, apology, affirmation, and uncertainty. Participants rated the effectiveness of sounds previously classified along a mechanical-musical spectrum. Results revealed a slight positive correlation between perceived effectiveness and musicality. These findings offer preliminary insight into how sound design may influence interpretability in social robot communication.