Echo-imaging exploits an environmental high-pass filter to access spatial information with a non-spatial sensor. Baier et al.
Description
We provide three datasets. Dataset 1 is from a formal psychophysical experiment where we measured echo-acoustic sensitivity functions for detecting different wave patterns in six bats. For Dataset 2 we measured the acoustic impulse responses of the stimuli used in the psychophysical experiment. In dataset 1, each file contains a variable “result” which contains recorded data from all trials that one bat did at one particular spatial frequency (e.g. 9 cyc/m). The data are arranged in a 5x181 array, where each column (except the very first) contains data from one trial. The rows store the following parameters: time code, wave amplitude (+- mm, i.e. /2 mm), side of reference stimulus (1=left, 2=right), side that bat chose, latency. From each file, the psychometric function of this bat at this spatial frequency can be obtained. For four bats, no full psychometric functions at 4 cyc/m could be recorded. Instead, the files (named e.g psychphys_data_bat2_disc_comp_4_16vs9_16.mat) contain 30 trials each of the stimulus with a spatial frequency of 4 cyc/m at maximum wave amplitude (+-16 mm = 32 mm) and the stimulus with a spatial frequency of 9 cyc/m at maximum wave amplitude (+-16 mm = 32 mm), that were presented alternately within a session. For dataset 2, we recorded impulse responses (IR) at four different ensonification angles: 30°, 45°, 60°, and 90°. The filename contains spatial frequency and wave amplitude (in =- mm) of the ripple disk as well as the ensonification angle (e.g. 18_04_ripple_plate_IR_90.mat means the ripple disk with 18 cyc/m, +-4 mm (= 8mm) was ensonified from directly above). “0_0” and “0_1” refer to the flat reference and control disks, respectively. Each file contains several variables: FS (sampling rate in Hz), cfn (ensonification stimulus: white noise filtered with the speaker’s compensatory impulse response), ir (impulse response, cut from xc), irlags (respective lags, cut from lags), lags (the lags at which the correlations are computed), rec (recorded signal), xc (result of the cross-correlation of rec and cfs). For dataset 3, we processed echoes from wave patterns (IR convolved with typical echolocation call) according to a physiologically plausible model of the auditory periphery (Wiegrebe 2008 Biol Cybern). The filename contains spatial frequency and wave amplitude (in =- mm) of the ripple disk. The two variables in the file are the NAP itself and the sampling rate FS.