Phase effects and profile analysis

Abstract

Randomizing the phase of the components of a tonal complex on each presentation has little effect on detection of an intensity increment of the central component. The complex consisted of eleven equal amplitude tones ranging from 200 to 5000 Hz. The spacing between adjacent components was equal on a logarithmic frequency scale. The signal was a sinusoid added in‐phase to the central, 1000‐Hz component. The overall sound pressure level of the sound was varied on each presentation according to a rectangular distribution with a range of 40 dB and a median sound pressure level per component of 45 dB. Over 50 complexes with different waveforms were generated by randomly selecting different starting phases for each component. Eight of these waveforms were selected, and each was presented as the complex for more than 500 trials in a 2AFC experiment. Thresholds for a signal added to each of these different complexes had a total range of only 2.4 dB. In a final test, we selected a different waveform on each presen...