pitch contour vs drone

pitch contour and drone both are nouns.

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

As nouns, drone is a hyponym of pitch contour; that is, drone is a word with a more specific, narrower meaning than pitch contour:

Other hyponyms of pitch contour include intonation pattern, droning, monotone, singsong.

pitch contour (noun)	drone (noun)
rise and fall of the voice pitch	stingless male bee in a colony of social bees (especially honeybees) whose sole function is to mate with the queen
	a pipe of the bagpipe that is tuned to produce a single continuous tone
	an aircraft without a pilot that is operated by remote control
	an unchanging intonation
	someone who takes more time than necessary; someone who lags behind

pitch contour (verb)	drone (verb)
	talk in a monotonous voice
	make a monotonous low dull sound