Musical stimuli: Human vs Artificial voice

Listening to music can affect time perception through musical, individual and contextual factors. Timbre, as a musical factor, was not yet studied in this context.. We tested whether timbre affected prospective duration estimates (DE) and/or the perceived speed of time’s passage (PoT). 76 participants listened to musical phrases in two versions, either sung by a female voice or a synthesized artificial voice. We assessed DE, PoT, and ratings for enjoyment, valence, arousal, and sound source naturalness. The results indicate that that timbre did not influence DE, but PoT was perceived as slower with the artificial voice. The human voice was considered as happier and more pleasant and natural, suggesting that this positive rating may be responsible for a faster PoT. Additional acoustical analyses of the stimuli confirmed evidence linking higher roughness with less enjoyment, while other relationships between acoustic features and emotion ratings remained less clear-cut. Our findings add to speech research reporting a preference for human-like timbres, support an independence between PoT and DE judgements, and a relationship between emotion and PoT. Results first suggest that timbre influences PoT through musical emotions, paving the way for future studies on how different timbres can shape time during music listening.

Our thank you and acknowledgment to the musicians Ana Luisa Gomes and Luis Castro who recorded this music.