Numerical simulation of the breathing-sound recognition. The simulations are based on four different breathing-sound parameters, namely (a) the sound level, (b) the breathing frequency, (c) the power spectrum of the breathing sounds and (d) the breathing-sound roughness. None of the simulations matches the behavioral performance of the vampire bats (Fig. 3). The breathing-sound simulation, however, matches the performance of the naïve human listeners (Fig. 5a), confirming the listeners' reports that they had tried to rely on breathing-frequency information.
Gröger and Wiegrebe BMC Biology 2006 4:18 doi:10.1186/1741-7007-4-18