One of three variables in the Large & Jones model of attention to rhythms. Phase describes the difference between the expected time of an onset of sound and the time when it actually occurs, in relation to the period between two expected onsets. The maximum phase occurs when the actual onset of sound occurs exactly between two expected onsets.
In humans, phase can undergo entrainment, because the oscillator in the brain that maintains phase is coupled to external oscillations of sound. This coupling causes phase to be drawn towards 0.