modulate

v. t. [ imp. & p. p. Modulated p. pr. & vb. n. Modulating ] [ L. modulatus, p. p. of modulari to measure, to modulate, fr. modulus a small measure, meter, melody, dim. of modus. See Mode. ] 1. To form, as sound, to a certain key, or to a certain portion. [ 1913 Webster ]

2. To vary or inflect in a natural, customary, or musical manner; as, the organs of speech modulate the voice in reading or speaking. [ 1913 Webster ]

Could any person so modulate her voice as to deceive so many? Broome. [ 1913 Webster ]

3. (Electronics) To alter the amplitude, frequency, phase, or intensity of (the carrier wave of a radio signal) at intervals, so as to represent information to be conveyed by the signal; -- a technique used to convey information by means of radio waves transmitted by one electronic device and received by another. [ WordNet 1.5 ]

v. i. (Mus.) To pass from one key into another. [ 1913 Webster ]