modulate

verb

1. 1

   vary the frequency, amplitude, phase, or other characteristic of (electromagnetic waves)

2. 2

   adjust the pitch, tone, or volume of

3. 3

   fix or adjust the time, amount, degree, or rate of

   regulate the temperature

   modulate the pitch

4. 4

   vary the pitch of one's speech

5. 5

   change the key of, in music

   modulate the melody