modulate
     v 1: change the key of, in music; "modulate the melody"
     2: of one's speech, varying the pitch [syn: {tone}, {inflect}]
     3: fix or adjust the time, amount, degree, or rate of;
        "regulate the temperature"; "modulate the pitch" [syn: {regulate}]
     4: adjust the pitch, tone, or volume of
     5: vary the frequency, amplitude, phase, or other
        characteristic of (electromagnetic waves)
Source: WordNet® 2.0