Page 49 - Summer 2006

Echoes from Providence
northern resident whales, dissimilarity matrices for the low frequency and high frequency calls were added to give an overall distance. Agreement with the perceptual classi- fication was 90 % which is amazingly good given the sim- ilarity of contours in several of the sub-groups.
Conclusion
Dynamic time warping shows promise for automatic classification of killer whale call types. One of the most exciting applications of this technique would be the ability to monitor the movements and habitat-preferences of killer whales just by tracking sounds heard at remote mon- itoring stations. This will only be possible with systems developed to automatically process and identify calls heard
at those locations so that the group producing them can be identified remotely.
Acknowledgment
JCB is very grateful to Dr. Eamonn Keogh for his MAT- LAB code which was adapted to give Fig. 3. Funding was pro- vided to PJOM by Woods Hole Oceanographic Institution’s Ocean Life Institute and a Royal Society fellowship.
Reference:
1 H. Yurk, L. Barrett-Lennard, J. K. B. Ford, and C. O. Matkin, “Cultural transmission within maternal lineages: vocal clans in resident killer whales in southern Alaska,” Animal Behaviour 63, 1103-1119 (2002).
Judy Brown is Professor of Physics Emerita at Wellesley College and Visiting Scientist at the Media Lab of the Massachusetts Institute of Technology. She is a Fellow of the Acoustical Society of America and has served on its Technical Committee on Musical Acoustics for over 10 years. Her interests lie in sig-
nal processing of musical sounds, and more recently classi- fication of vocalizations of marine mammals.
Patrick Miller is a Senior
Research Fellow at the Sea
Mammal Research Unit in the
University of Saint Andrews in
Scotland, and recent holder of a
Royal Society USA/Canada
Fellowship. Miller completed the
Ph.D. on vocal signals of killer
whales in 2000 jointly from the
Woods Hole Oceanographic
Institution and the Massachusetts Institute of Technology. His research focuses on acoustic communication and social behavior of marine mammals, foraging and diving.
This article is based on paper 5aABb2 at the 151st ASA meeting in Providence.
At the College of Fellows luncheon at the Providence meeting Dr. Amar Bose gave an interesting lecture on a novel suspension system his company has developed for automobiles. Each of the four wheels is independently controlled by a computer which is modeled to react to pot- holes, bumps, and turns. A fascinating video showed cars leaning into turns (more like a motorcycle) rather than out. Also cars were shown smoothly going over speed bumps, which raised one obvious question from the audi- ence (and maybe the police). The four wheel controllers can also be directly controlled, so that by appropriately raising and lowering the front and rear wheels the car was made to jump over a small hurdle—impressing everyone in attendance.
Dr. Amar Bose (center) is joined by Leo Beranek and Jan Weisenberger, Chair of College of Fellows. (Photo by Charles Schmid)
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