MODULATION
modulation
(noun) the act of modifying or adjusting according to due measure and proportion (as with regard to artistic effect)
modulation
(noun) (electronics) the transmission of a signal by using it to vary a carrier wave; changing the carrier’s amplitude or frequency or phase
modulation, inflection
(noun) a manner of speaking in which the loudness or pitch or tone of the voice is modified
intonation, modulation, pitch contour
(noun) rise and fall of the voice pitch
transition, modulation
(noun) a musical passage moving from one key to another
Source: WordNet® 3.1
Etymology
Noun
modulation (countable and uncountable, plural modulations)
The process of applying a signal to a carrier, modulating.
The variation and regulation of a population, physiological response, etc.
(music) A change in key.
Source: Wiktionary
Mod`u*la"tion, n. Etym: [L. modulatio: cf. F. modulation.]
1. The act of modulating, or the state of being modulated; as, the
modulation of the voice.
2. Sound modulated; melody. [R.] Thomson.
3. (Mus.)
Definition: A change of key, whether transient, or until the music becomes
established in the new key; a shifting of the tonality of a piece, so
that the harmonies all center upon a new keynote or tonic; the art of
transition out of the original key into one nearly related, and so
on, it may be, by successive changes, into a key quite remote. There
are also sudden and unprepared modulations.
Source: Webster’s Unabridged Dictionary 1913 Edition