Name that percussive tune: Associative memory and amplitude envelope.
Our lab’s research has repeatedly documented significant differences in the outcomes of perception experiments using flat (i.e. sustained) vs. percussive (i.e. decaying) tones [1, 2]. Some of these findings contrast with wellestablished theories and models, and we suspect this discrepancy stems from a traditional focus on flat tones in psychophysical research on auditory perception. To explore this issue, we surveyed 94 articles published in Attention, Perception & Psychophysics, classifying the temporal structure (i.e. amplitude envelope) of each sound using five categories: flat (i.e. sustained with abruptly ending offsets), percussive (i.e. naturally decaying offsets), click train (i.e. a series of rapid sound-bursts), other, and not specified (i.e. insufficient specification with respect to temporal structure). The use of flat tones (31%) clearly outnumbered percussive (4.5%). This under-utilization of percussive sounds is intriguing, given their ecological prevalence outside the lab [3,4]. Interestingly, 55% of the tones encountered fell within the not specified category. This is not indicative of general neglect, as these articles frequently specified other details such as spectral envelope, headphone model, and model of computer/synthesizer. This suggests that temporal structure’s full importance has not traditionally been recognized, and that it represents a rich area for future research and exploration.