Modulate \Mod"u*late\, 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.

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

Could any person so modulate her voice as to deceive so many? --Broome.

Source: Webster's Revised Unabridged Dictionary (1913)