Hierarchical event detection
Neil P. McAngus Todd · The Journal of the Acoustical Society of America · 1992
Research on musical performance has shown that expressive variations in tempo, dynamics, etc. not explioit in a score can be acounted for by structural factors such as phrasing and rhythm [N. P. McAngus Todd, J. Acoust. Soc. Am. 91, 3540–3550 (1992)]. There now exists a number of models that attempt to recover rhythmic structure from a performed sequence [H. C. Longuet-Higgins, Nature 263, 646–653 (1976); P. Desain, Music Percept. 9(4), 439–454 (1992)]. However, they do not address the question of how the human auditory system might detect temporal events before such higher level processing. A low-level representation is proposed, analogous to the primal sketch in vision [D. Marr and E. Hildreth, Proc. R. Soc. London Ser. B 207, 187–217 (1980)], enocoding intensity changes at different time scales via an array of filters tuned at very low infrasonic frequencies. This representation could act as a front end to perceptual models. Various outputs from an analog implementation of the filter array are demonstrated including music, speech, poetry, and bird song.