Subject: Re: regarding bat's vocalizaion and its signal structure From: Harry Erwin <harry.erwin(at)SUNDERLAND.AC.UK> Date: Fri, 1 Jul 2005 10:08:21 +0100On 1 Jul 2005, at 07:42, J. Gwan Lim wrote: > Dear Lists > > Recently I've read Schnitzler's paper titled ' Echolocation by > insect-eating bats' and it was so amusing. He tried to map bat's > signal > structure into typical echolocation task and distinct functional > groups. > He said, narrow band signals is good for target classification and > broad > band for target localization. > A lot of this analysis parallels engineering work on radar detection and tracking in clutter. The broad band signals tend to be doppler- tolerant, so they give a good localization that is insensitive to relative velocity. In the big brown bat, the search signals have a significant continuous-wave (narrow band) tail, which can pick out moving targets in background clutter. Long-range acquisition and tracking signals seem to be doppler-tolerant. These bats appear to use bursts of signals for accurate localization at medium to short range, and 'terminal buzzes' to classify targets at medium range and control approach to targets at short range. I'm looking at neural mechanisms for representing location and velocity, and I strongly suspect the bursts and buzzes are used to measure relative target velocity directly as it is unlikely that the CNS possesses mechanisms for doing vector arithmetic. > > After reading it, I am wondering if there is any paper to specify and > analyze the reason the above statements about correlation between > signal > frequency band and its functional task. Could you recommend any > book or > paper? > > Griffin, D. R. (1958). Listening in the Dark. Ithaca, New York, Comstock Publishing Associates. Popper, A. N. and R. R. Fay, Eds. (1995). Hearing by Bats. Springer Handbook of Auditory Research. New York, New York, Springer-Verlag. Altes, R. A. (1995). "Signal Processing for Target Recognition in Biosonar." Neural Networks 8(7/8): 1275-1295. Kalko, E. K. V. and H.-U. Schnitzler (1998). How Echolocating Bats Approach and Acquire Food. Bat Biology and Conservation. T. H. Kunz and P. A. Racey. Washington and London, Smithsonian Institution Press: 197-204. Müller, R. and R. Kuc (2000). "Foliage Echoes: A Probe into the Ecological Acoustics of Bat Echolocation." Journal of the Acoustical Society of America 108(2): 836-845. Nachtigall, P. E. and P. W. Moore, Eds. (1988). Animal Sonar: Processes and Performance, Plenum Press. > > -- Harry Erwin, PhD, Senior Lecturer of Computing, University of Sunderland. Computational neuroscientist modeling bat bioacoustics and behavior. http://osiris.sunderland.ac.uk/~cs0her