Can an inner ear infection be seen with an otoscope?

Not commonly: If you mean sudden hearing loss or dizziness that a doctor has diagnosed as vestibular neuritis or labyrinthitis, usually you cannot see signs of this with an otoscope. However, sometimes similar symptoms are also brought on by a middle ear infection (acute otitis media) and that would be visible with an otoscope.

No: You cannot see the inner ear with an otoscope. To visualize the inner ear, which is encased in bone, you need an mri.

No: The inner ear is housed in dense bone (densist in the body) behind the ear drum. "inner ear infections" - labrynthitis are usually diagnosed with a good history.

No: The middle ear is visible across the tympanic membrane but the inner ear is burried deep within the temporal bone and cannot be visualized on physical exam.

Define "inner ear": I have seen some people describe the typical middle ear infection as being an inner ear ( instead of canal) infection. The infections of the "inner ear" meaning the organ of corti where sound is processed cannot be seen by anyone with any instrument.