Source : Webster's Revised Unabridged Dictionary (1913)

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.