1 [VN] (formal) to change the quality of your voice in order to create a particular effect by making it louder, softer, lower, etc.
2 [V] ~ (from sth) (to / into sth) (music) to change from one musical KEY (= set of notes) to another
3 [VN] (technical) to affect sth so that it becomes more regular, slower, etc:
drugs that effectively modulate the disease process
4 [VN] (technical) to change the rate at which a sound wave or radio signal VIBRATES (= the FREQUENCY) so that it is clearer
modulation noun [U,C]
