cart icon

Research Findings

Auditory Beats in the Brain

By Gerald Oster, Scientific American, October 1973

Slow modulations called binaural beats are perceived when tones of different frequency are presented separately to each ear. The sensation may show how certain sounds are processed in the brain.

If two tuning forks of slightly different pitch are struck simultaneously, the resulting sound waxes and wanes periodically. The modulations are referred to as beats; their frequency is equal to the difference between the frequencies of the two original tones.

Binaural beats have been widely regarded as a mere curiosity. A recent textbook on hearing does not mention them at all. Yet the measurement of binaural beats can explain the processes by which sounds are located -- a crucial aspect of perception. It is possible that hormonally induced physiological behavior changes may be made apparent by measuring the binaural-beat spectrum.