reverberation vs reflectivity

reverberation and reflectivity both are nouns.

Word	Noun	Adjective	Verb	Adverb
reverberation	Yes	No	No	No
reflectivity	Yes	No	No	No

As nouns, reflectivity is a hypernym of reverberation; that is, reflectivity is a word with a broader meaning than reverberation:

reverberation: the repetition of a sound resulting from reflection of the sound waves
reflectivity: the ability to reflect beams or rays

Other hypernyms of reverberation include reflection, reflexion.

reverberation (noun)	reflectivity (noun)
the repetition of a sound resulting from reflection of the sound waves	the ability to reflect beams or rays
a remote or indirect consequence of some action	the capability of quiet thought or contemplation
	the fraction of radiant energy that is reflected from a surface