The timing of acoustic events is central to human speech and music. Tempo tends to be slower in aesthetic contexts: rates in poetic speech and music are slower than non-poetic, running speech. We tested whether a general aesthetic preference for slower rates can account for this, using birdsong as a stimulus: It structurally resembles human sequences but is unbiased by their production or processing constraints. When listeners selected the birdsong playback tempo that was most pleasing, they showed no bias towards any range of note rates. However, upon hearing a novel stimulus, listeners rapidly formed a robust, implicit memory of its temporal properties, and developed a stimulus-specific preference for the memorized tempo. Interestingly, tempo perception in birdsong stimuli was strongly determined by the individual, internal preferences for rates of 1–2Hz. This suggests that processing complex sound sequences relies on a default time window, while aesthetic appreciation appears flexible, experience-based, and not determined by absolute event rates.
Listening to birdsong reveals basic features of rate perception and aesthetic judgments
Possible relationship between acoustic rates/perceived tempos and aesthetic appreciation, and their predicted influence on experimental outcome. A: Acoustic events unfold at an indefinite range of tempos/event rates, the total of which is symbolized by the large dark circle. Some rates are perceivable to human listeners (lighter circle). Perception is biased instead of uniform across the perceivable rates (symbolized by irregular shape in head). B: Some perceived rates may be inherently more aesthetic than others (1 and 2), either because of an independent aesthetic rate preference (e.g. for intermediate rates for their ease of processing (1)), or based on experience (e.g. natural, typical birdsong rates would be preferred for birdsong (2)). Alternatively, aesthetic appreciation is independent of absolute event rate (3). C: Predicted effect of the 3 scenarios on experimental outcome. An aesthetic preference for intermediate rates would result in narrower preferred than presented rates (1), an experience-based preference in overlapping natural-sounding and preferred rates (2), and an aesthetic preference for which absolute rates are irrelevant in similar presented and preferred rates (3). Natural-sounding rates may differ from depicted (no claims are made by preference scenarios about naturalness categorization; hence dashed lines).
Max Planck Institute for Empirical Aesthetics
