Modulation characteristics of the network.

(A,B) Normalized modulation transfer function for layers -left- and -right- displayed in axes of rate (temporal modulations in Hz)—scale (spectral modulations in cycles per octave). (C,D) Overlaid on each transfer function is a contour plot of agglomerative clusters in spectro-temporal modulation space for layers -left- and -right-.(E) Noise ripples are used to analyze the spectro-temporal tuning of the model at different stages. They are noise signals that are modulated in time and frequency. (F) Example filter tuning from layer for 4 nodes exhibiting tuning to harmonicity (top, left), onset (top, right), a slow neuron (bottom, left) and a fast neuron (bottom, right). The filter response profiles have been interpolated using a cubic function for display purposes.