Figure 1.

Waveform (top) and spectra (bottom) of the stimuli used in this study. The signal-to-OFM ratio in this example is 0 dB (defined as the maximum amplitude of the signal pip divided by the amplitude of the carrier of the OFM). Left, RF condition, containing only the signal and the OFM. Middle, CM condition with six FBs added in phase with the OFM envelope. Right, CD condition with six FBs added 180° out of phase with the OFM envelope. For each of the top panels, signal position in the waveform is indicated by the bracketed bar between the dotted lines. Signal and OFM frequency in this example are 700 Hz, the spacing of the FBs is 100 Hz, and the frequency separation between the OFM and the nearest FB is 200 Hz.