Fig 1.
Illustrations of click waveforms.
Illustrations of waveforms of three clicks for each of the three echolocators.
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).
Table 1.
Variability of spectrum peaks in frequency and amplitude.
Fig 3.
Top row: Azimuth directivity diagrams for EE mouth-clicks at 40cm. Markers indicate average of measured data; shaded regions denote 1 SD around the average; red line is fit of a modified cardioid. Middle row: Azimuth directivity diagrams for EE mouth-clicks at 100cm. Symbol and colour coding as in top row. Bottom row: Elevation directivity diagrams for EE mouth-clicks. Markers indicate average of measured data; shaded regions denote 1 SD around the average.
Fig 4.
Azimuth dependent directivity diagrams for speech based on [20] (magenta) and [21] (cyan) and for clicks from EE1-EE3 (red lines and blue symbols; plotted as in Fig 3). All measurements from 100cm.
Fig 5.
Frequency dependent directivity diagrams.
Top row: Azimuth frequency-dependent directivity diagrams for EE mouth-clicks at 40cm. Lines indicate average of measured data; shaded regions denote 1 SD around the average; different colours denote different frequency bands. Middle row: Azimuth frequency-dependent directivity diagrams for EE mouth-clicks at 100cm. Line and colour coding as in top row. Bottom row: Elevation frequency-dependent directivity diagrams for EE mouth-clicks. Line and colour coding as in top row.
Fig 6.
Figures show envelope estimate for three EE1 Clicks, along with the mean squared error (MSE) of the estimate.
Table 2.
Synthetic click parameters for EE1, EE2, and EE3.
Fig 7.
Synthetic clicks plotted for EE1 (left), EE2 (middle), and EE3 (right) in the frequency-time-domain (top), frequency-domain (middle), and time-domain (bottom).