Product Overview
Not all periodic oscillations lie within the range of audible frequencies,but this does not mean that you cannot hear them. For example, a violinist’s vibrato may take the form of an oscillation at,say,5Hz,while the growl produced by over-blowing a brass instrument may occur at 18Hz. Even in isolation, you may hear a periodic waveform at subsonic frequencies - for example, a clock oscillator with an output of 1Hz will sound like a series of repeating clicks. (Strictly speaking, these have a high bandwidth due to the transient nature of the waveform, and you would not hear a sine wave at the same frequency, but that is not the point.)
Synthesisers have a class of oscillators- Low Frequency Oscillators (LFOs) - that create these, and many other, effects.They can add vibrato to a sound, produce growl, act as low frequency clocks and, on some synthesisers, double as audio frequency oscillators.
