Which of the following is a condition of increasing growth of spongy bone in the otic capsule?

Otosclerosis is a condition characterized by the abnormal growth of bone in the middle ear and the otic capsule, which can lead to hearing loss. The process involves the replacement of normal bone with spongy bone, particularly affecting the stapes bone in the ear, which can become immobilized as a result. This increased growth of spongy bone is a hallmark of otosclerosis, distinguishing it from other ear-related conditions.

In contrast, tinnitus is a symptom rather than a condition characterized by ringing or noise in the ears, and does not specifically involve the growth of bone. Labyrinthitis refers to inflammation of the inner ear structures, often due to infection, affecting balance and hearing but unrelated to bone growth. Vestibular neuritis involves inflammation of the vestibular nerve, leading to balance issues, and also does not correlate with changes in bone structure.

Thus, otosclerosis stands out as the condition linked to the increased growth of spongy bone in the otic capsule, making it the correct choice among the options provided.