modulation vs pitch contour

modulation and pitch contour both are nouns.

Word	Noun	Adjective	Verb	Adverb
modulation	Yes	No	No	No
pitch contour	Yes	No	No	No

As nouns, modulation and pitch contour are synonyms defined as:

Other synonyms of modulation include intonation.

modulation (noun)	pitch contour (noun)
the act of modifying or adjusting according to due measure and proportion (as with regard to artistic effect)	rise and fall of the voice pitch
(electronics) the transmission of a signal by using it to vary a carrier wave; changing the carrier's amplitude or frequency or phase
a musical passage moving from one key to another
rise and fall of the voice pitch
a manner of speaking in which the loudness or pitch or tone of the voice is modified