Subset of the amplitude-modulated binaural beat (AMBB) stimuli used in the experiment. Only the 1st 150 ms of the 1-s stimuli are plotted. For the stimuli in this figure, a mean carrier frequency of 288 Hz and of contralateral frequency (fcontra) > ipsilateral frequency (fipsi) was used. A: parametrical change of the AMBB frequency (left), affecting both amplitude-modulation (AM) rate and beat rate. In this panel, the start interaural-phase difference (IPD) at modulation minimum was kept constant at −90°. B: parametrical change of the start IPD (left). The start IPD is defined as the IPD in each modulation minimum. Here, the AMBB frequency was kept constant at 16 Hz. In addition to the fully AM binaural beats with 8 different start IPDs, a control condition with no AM was used (bottom row).