Comparison between the importance of spectral and temporal features of the envelope parameters.

<p>Calculations are shown separately for females (a) and males (b). Histograms represent the relative decrease as a percentage in the probability of correct classification (PCC) observed when removing the spectral (left) or temporal (right) parameters from the DFA. Error bars show two-standard errors estimated by bootstrapping. For each distance, except for 128 m for females, the changes observed by removing spectral information vs. the temporal information are significantly different (all <i>p</i> values <10⁻⁵ using a two-sided t-test).