Audibility of Binaural Beats Depending on Frequency and Modulation Rate

Spatial impression is conventionally created with reverberators or decorrelators to diffuse sound sources in a mix. Another approach is to generate the signal of a sound source with its harmonic structure from scratch and to manipulate the spatial impression directly. This synthesis is based on the individual spectral lines, which must not be identical (diotic) for headphone playback, but must be very similar (dichotic). Binaural beats fulfill this property when the frequency differences of the ear signals are small. The degree of audibility of binaural beats with slight frequency differences depends on the pitch and has not been investigated in the past. The degree of audibility was determined in an experiment using the single-stimulus method at the three bark scale center frequencies of 50 Hz, 250 Hz, and 450 Hz. The criterion for the degree of audibility is the detection of pulsations in the signal.