unhearable vs supersonic

unhearable and supersonic both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unhearable	No	Yes	No	No
supersonic	No	Yes	No	No

unhearable (adjective)	supersonic (adjective)
impossible to hear; imperceptible by the ear	(of speed) greater than the speed of sound in a given medium (especially air)
	having frequencies above those of audible sound