Tremolo is the audio effect created from using amplitude modulation. Examples of the effect can be found in many styles of music from different eras in time. Tremolo creates the perception of a pulsating signal.
There are two main controls of the effect. First, the “rate” or “speed” controls how often the amplitude pulses occur. This is controlled by modifying the frequency of the LFO modulator. Second, the “depth” or “intensity” controls the strength of the effect. This is controlled by modifying the amplitude of the LFO modulator.