modulate (
http://definr.com/modulate)
v 1: change the key of, in music; "modulate the melody"
2: of one's speech, varying the pitch [syn:
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)