ABSTRACT
When two pure tones are within a few Hz of each other, they produce a waveform that has a highly prominent low frequency pattern in overall amplitude. One can easily see the waxing and waning of the resultant waveform (Fig. V .8 of Section V .1.2.3) as well as hear it (Demonstration 4. Section Vl.2.1.2 discusses how beating interacts with the masking effect of one pure tone on another, making it easier to detect the signal than would otherwise be expected.
