Comparing LS with SC.

<p><b>(A)</b> From left to right: the AN population response for a harmonic complex with the 1^st – 4^th harmonics. The y-axis is the CFs normalized by the fundamental frequency, in a linear scale (f₀ = 240 Hz). The x-axis indicates the post-stimulus time (between 10ms to 15ms). Next, the <b>h</b> coefficient vectors for the LS case (λ = 0.0) and for the sparse case (λ = 0.01). <b>(B)</b> Same as in (A) but for a complex tone stimulus that contains the harmonics 10^th–13^th. Note that for the lower harmonic stimulus (A), the results between the two cases, i.e., <b>h</b>_LS vs. <b>h</b>_SC, are almost identical. On the other hand, for the stimuli with the higher harmonics (B), the difference is more substantial. Specifically, there are much more nonzero coefficients in <b>h</b>_LS than in <b>h</b>_SC that are unrelated to the original spectrum structure of the signal (compare with the FTs in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005338#pcbi.1005338.g002" target="_blank"><b>Fig 2</b>A</a>).