Fig 1. Current approach limitations.

A) Frequency sensitivity, defined as the minimum discernable change at a given frequency, in both starlings and humans. B) Mapping between different frequency scaling metrics. C) Normalized frequency sensitivities in each frequency scale. Sensitivity values are normalized to the mean within each frequency scale. D) Two identical Star-scale spectrograms (X and Y) from each other by only one frequency band, corresponding to one Star. The distance spectrogram (X-Y) is calculated from pixel-wise subtraction between X and Y.