Workpackage 1.3: Analysis of array morphology
From the shape of a bat noseleaf, we can estimate which region in
space the sound emitted by the bat will illuminate. Likewise, we can
use the shape of the outer ear to predict the spatial sensitivity of
the bat for echoes. The shape of both of these regions (for emission
and reception) depends on the frequency of the sound. Hence we can
draw a boundary (an "iso-surface") in three-dimensional space around
these regions for each frequency. Here surfaces colored with red hues
represent high frequencies whereas blue hues represent low
frequencies.
Computer models allow us to predict how the noseleaves and outer ears
of bats function as sonar antenna for emitting and receiving
ultrasound.
For each three-dimensional position around the noseleaf or the ear, we can estimate how much sound energy from the noseleaf would be present and how sensitive the ear would be for a sound source (or sound-reflecting target) at this position. Through computer manipulation of the digital shape representations the role of individual anatomical features can be studied experimentally.
For example, furrows in the noseleaves may be filled in as shown in the Figure. In this case, it was shown that the furrows function to widen the biosonar beam at the lower (blue) frequencies because of cavity resonances like the once elicited by blowing over the top of an empty bottle.
For each three-dimensional position around the noseleaf or the ear, we can estimate how much sound energy from the noseleaf would be present and how sensitive the ear would be for a sound source (or sound-reflecting target) at this position. Through computer manipulation of the digital shape representations the role of individual anatomical features can be studied experimentally.
For example, furrows in the noseleaves may be filled in as shown in the Figure. In this case, it was shown that the furrows function to widen the biosonar beam at the lower (blue) frequencies because of cavity resonances like the once elicited by blowing over the top of an empty bottle.
cilia_pm@fz-juelich.de