What do the two tones sound like when they are combined? Add a second oscillator (by clicking the Add button in the lower right-hand corner of SoundScope). Set one oscillator to 100 Hz and the second oscillator to 200 Hz. A single cycle of the combined waveform looks like this. A complete cycle still takes the same amount of time (one-tenth of a second).

However, the waveform is no longer a pure tone. Combining the 100 Hz tone with a 200 Hz tone results in a complex wave form. A complex wave form consists of two or more frequencies mixed together. Addition of the 200 Hz tone results in a double peak in a single cycle – one large peak and a second smaller one.