sprechstimme vs phonation

sprechstimme and phonation both are nouns.

Word	Noun	Adjective	Verb	Adverb
sprechstimme	Yes	No	No	No
phonation	Yes	No	No	No

As nouns, phonation is a hypernym of sprechstimme; that is, phonation is a word with a broader meaning than sprechstimme:

sprechstimme: a style of dramatic vocalization between singing and speaking
phonation: the sound made by the vibration of vocal folds modified by the resonance of the vocal tract

Other hypernyms of sprechstimme include vocalisation, vocalism, vocalization, voice, vox.

sprechstimme (noun)	phonation (noun)
a style of dramatic vocalization between singing and speaking	the sound made by the vibration of vocal folds modified by the resonance of the vocal tract