Dear Colleagues,
I would like to draw your attention to the following paper, published in the
January edition of the Journal of the Acoustical Society of America:
Deecke, V.B. and Janik, V.M. 2006. Automated categorization of bioacoustic
signals: Avoiding perceptual pitfalls. Journal of the Acoustical Society of
America 119(1): 645-653.
ABSTRACT
Dividing the acoustic repertoires of animals into biologically
relevant categories presents a widespread problem in the study of
animal sound communication, essential to any comparison of repertoires
between contexts, individuals, populations, or species. Automated
procedures allow rapid, repeatable, and objective categorization, but
often perform poorly at detecting biologically meaningful sound
classes. Arguably this is because many automated methods fail to
address the nonlinearities of animal sound perception. We present a
new method of categorization that incorporates dynamic time-warping
and an adaptive resonance theory (ART) neural network. This method was
tested on 104 randomly chosen whistle contours from four captive
bottlenose dolphins (Tursiops truncatus), as well as 50 frequency
contours extracted from calls of transient killer whales (Orcinus
orca). The dolphin data included known biologically meaningful
categories in the form of 42 stereotyped whistles produced when each
individual was isolated from its group. The automated procedure
correctly grouped all but two stereotyped whistles into separate
categories, thus performing as well as human observers. The
categorization of killer whale calls largely corresponded to visual
and aural categorizations by other researchers. These results suggest
that this methodology provides a repeatable and objective means of
dividing bioacoustic signals into biologically meaningful categories.
KEYWORDS
Automated categorization, automated classification, killer whale, bottlenose
dolphin, signature whistle, neural network, call recognition, repertoire size,
dynamic time-warping
Best regards
Volker Deecke
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Volker Deecke, Ph.D.
Marine Mammal Research Unit Cetacean Research Lab
University of BC Vancouver Aquarium Marine Science Centre
AERL Bldg., 2202 Main Mall P.O. Box 3232
Vancouver, BC, V6T 1Z4 Vancouver, BC V6B 3X8
Canada Canada
Phone: +1.604.822.9150 +1.604.659.3429/3430
Fax: +1.604.822.8180 +1.604.659.3599
WWW: http://www.marinemammal.org/MMRU
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