“…For the measurement of best-frequency tuning, data acquisition comprised ϳ120 total s, during which the multitone stimulus (see above) was presented. Receptive fields were derived individually for each pixel by forward correlation, i.e., calculating the average response time locked to the onset of tone pips of each frequency (Farley and Noreña 2013;Valentine and Eggermont 2004). The best frequency of a pixel was then defined as the frequency eliciting the maximal response, across all frequencies and latencies.…”