A bit of deafness in the left ear can itself be divided into two conditions: one, caused by inflammatory diseases; and two, caused by neurological diseases. Inflammatory diseases such as otitis externa, boils in the external ear canal, granuloma of the external ear canal, and cerumen embolism, the middle ear can have tympanic membrane perforation, otitis media, mastoiditis, and cholesteatoma formation, and the inner ear such as labyrinthitis and vestibular neuritis, among others, can lead to deafness. Neurological ones such as inner ear vertigo, sensorineural deafness, Meniere’s disease, and damage to the nerves in the inner ear can lead to neurological deafness. In this case, electrical audiometry or acoustic impedance, as well as endoscopy, may be considered to clarify the diagnosis. There are some cases of neurological damage to the inner ear due to trauma, lateral skull base fracture or temporal bone fracture, which are also classified as neurological deafness.