Yes, OTOSCOPE is a Scrabble word!

Letter values in Scrabble US: O 1, T 1, O 1, S 1, C 3, O 1, P 3, E 1.

Is it a valid word?

OTOSCOPE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

medical instrument consisting of a magnifying lens and light; used for examining the external ear (the auditory meatus and especially the tympanic membrane)

Not playable in Scrabble US: AURISCOPE, AUROSCOPE.