—v.t. 1. to regulate by or adjust to a certain measure or proportion; soften; tone down.
2. to alter or adapt (the voice) according to the circumstances, one's listener, etc.
3. Music. a. to attune to a certain pitch or key.
b. to vary the volume of (tone).
4. Telecommunications.to cause the amplitude, frequency, phase, or intensity of (a carrier wave) to vary in accordance with a sound wave or other signal, the frequency of the signal wave usually being very much lower than that of the carrier.
—v.i. 1. Telecommunications. a. to modulate a carrier wave.
b. CB Slang.to talk; visit: Enjoyed modulating with you. 2. Music.to pass from one key to another: to modulate abruptly from A to B flat.