Waveplots and spectrograms of the sound of a click (highlighted with black arrows) and its echo (highlighted with green arrows) recorded in the left (L) and right (R) ears of EB and LB (sampling rate 44.1 kHz) (Sound S1 and Sound S2). Both EB and LB made the clicks in the presence of a position marker (shown in 1B) located straight ahead. Spectrograms were obtained using an FFT window of 256 samples, corresponding to approximately 5.6 ms in our recordings. Waveform plots and spectrograms are for illustration. While the exact properties of the click and its echo (e.g. loudness, timbre) are specific to the person generating the click as well as the sound reflecting surface, prominent characteristics of clicks are short duration (approximately 10 ms) and broad frequency spectra, both of which are evident in the plots.