Gennadi
Zaslavski
University
authority for applied research,
RAMOT, Tel-Aviv University, Israel
gennadi.zaslavski@gmail.com
Theoretical time resolution of the
bottlenose dolphin echolocation clicks is as high as 15 -20 microseconds. Given
a very broad frequency range of the bottlenose dolphin hearing extending from
5-10 kHz to as far as 130-135 kHz the dolphin sonar time resolution could be as
high as the theoretical time resolution of the echolocation clicks.
Multi-highlight structure of a target echo in response to brief echolocation
clicks results in the echo frequency spectrum being rippled, with local maxima
and minima at different frequencies. There are many computer simulated models
of echo-processing in dolphins. Most of these models are based on the frequency
domain analysis of target echoes although the time domain features of an echo
are normally more conspicuous than the frequency domain features. As long as an actual time resolution of the
dolphin sonar is not known it is impossible to choose between the frequency and
time domain analysis. In this presentation I discuss some data we obtained in
behavioral experiments with bottlenose dolphins indicating the auditory time
resolution as high as around 20 microseconds which is the theoretical time
resolution of the bottlenose dolphin echolocation clicks. With this high auditory time resolution
bottlenose dolphins appear capable of extracting the time domain features of
echoes from most of real targets and phantom echoes tested in numerous behavioral
experiments.