internal ear vs inner ear

internal ear and inner ear both are nouns.

Word	Noun	Adjective	Verb	Adverb
internal ear	Yes	No	No	No
inner ear	Yes	No	No	No

As nouns, internal ear and inner ear are synonyms defined as:

internal ear and inner ear: a complex system of interconnecting cavities; concerned with hearing and equilibrium

Other synonyms of internal ear include labyrinth.

internal ear (noun)	inner ear (noun)
a complex system of interconnecting cavities; concerned with hearing and equilibrium	a complex system of interconnecting cavities; concerned with hearing and equilibrium