Fig 1.

Orienting responses to rising- and falling-intensity complex tone stimuli. (A) Time-amplitude waveforms and power spectrum of the complex tone (based on a 1-kHz triangle waveform) used in condition 1. (B) Duration of head-orienting responses to rising- and falling-intensity complex tones. Black bars represent responses to rising-intensity sounds, whereas white bars represent falling-intensity sounds. The y axis represents duration (in s) of first head turn as measured from the onset of the sound.