Mouth-clicks used by blind expert human echolocators – signal description and model based signal synthesis
Fig 2
Frequency content of clicks for all echolocators.
Top: Averaged spectrograms; Middle: Averaged power spectral density (PSD) plots; shaded regions denote 1 SD around the average; Bottom: Waterfall plots showing a set of PSD estimates for a subset of clicks and the average PSD estimate (black line at back).