Isochronic tones

Isochronic tones are regular beats of a single tone that are used alongside monaural beats and binaural beats in the process called brainwave entrainment. At its simplest level, an isochronic tone is a tone that is being turned on and off rapidly. They create sharp, distinctive pulses of sound.

Isochronic tones are tones of any frequency that recur at regular intervals, usually rapid. Isochronic tones can quantitatively be distinguished by both the frequency or pitch of the tone itself, and by the interval or frequency of repetition of the tone. There is no reliable research that confirms any claims of health benefits by listening to isochronic tones.

https://en.wikipedia.org/wiki/Isochronic_tones