“…Previously, sparse coding (Olshausen & Field, 1996) and ICA-related-methods have been applied to audio data to investigate the basic properties of cells in the primary auditory cortex (A1) (Klein, König, & Körding, 2003;Terashima & Hosoya, 2009;Terashima, Hosoya, Tani, Ichinohe, & Okada, 2013). More recently, topographic ICA (TICA) (Hyvärinen et al, 2001) was employed to analyze spectrogram data, and feature maps were learned which are similar to the tonotopic maps in A1 (Terashima & Okada, 2012).…”