Fig. 4.
Distribution of best azimuth for single P responses in 2D neurons (A). Representative auditory spatial receptive fields in 2D neurons (B, C). Single sounds were broadcast at 2/sec at various sound levels above the unit’s minimum threshold. The receptive field in B was mapped using a tone stimulus of 24 kHz, 2 msec in duration. This unit also fired strongly to FM sounds. The unit in C was studied using the standard two-harmonic stimulus. Legend: 84 dB SPL, solid line; 74 dB SPL, dotted line; 64 dB SPL, dashed line; 54 dB SPL, dash–dot line. D, Sensitivity to elevation in 2D neurons. Units were tested at their best azimuth, and each curve represents a different unit.