Read the dictionary definition of modulate. All definitions for this word.
1. vary the frequency, amplitude, phase, or other characteristic of (electromagnetic waves)
2. adjust the pitch, tone, or volume of
3. fix or adjust the time, amount, degree, or rate of
1. regulate the temperature
2. modulate the pitch
4. vary the pitch of one's speech
5. change the key of, in music
1. modulate the melody