Some patients say they have a history of ear discharge and after treatment their ear no longer drains and they have been examined by a doctor who says the tympanic membrane perforation has healed and the otitis media is completely healed, but their hearing is worse than when the discharge was present. Why is this? 1. Sound waves are transmitted from the outer ear to the inner ear via the middle ear. Sound waves are transmitted through the outer ear and middle ear to the inner ear to produce a sensory tone, which becomes a nerve impulse that travels along the auditory nerve to the auditory center, where it is analyzed and synthesized to make a corresponding response. In general, the middle ear is more important than the outer ear for sound transmission. The middle ear cavity is a small cavity with six walls inside and outside, and a volume of only 2 cubic millimeters. The two walls are connected to the inner ear and the tympanic membrane by three smallest bones in the human body, which act as a bridge to transmit sound waves. These three small bones are arranged into a “chain of bones”, which works cleverly to make the middle ear not simply conduct sound waves like the outer ear, but also to increase pressure and amplify sound. 2. Why hearing loss after otitis media? When you have purulent otitis media, the inflammation can perforate the eardrum and cause clinical manifestations such as ear pus and hearing loss. The inflammation involves the auditory bone, causing it to corrode and interrupt the auditory chain, and the middle ear pressure boosting and sound amplification completely disappears, resulting in more pronounced hearing loss. Long-term pus flow, especially in cholesteatoma type otitis media, can lead to reduced or absent inner ear sensory function due to toxins or bacteria entering the inner ear, resulting in mixed deafness on hearing examination. 3. Why is hearing worse after otitis media healing than when there is abscess? With the above introduction, this problem can be understood. Because middle ear inflammation can both perforate the tympanic membrane and interrupt the auditory bone chain, or due to scarring and calcium deposition, the auditory bone activity is obstructed or fixed, after treatment, the inflammation control reaches the dry ear, the tympanic membrane perforation is healed, but the auditory bone chain is still interrupted or fixed, the external sound waves cannot reach the inner ear through the auditory bone chain by the healed tympanic membrane, which is equal to people listening to the sound outside an empty room apart, than listening to the sound outside an open room. This is the same as listening to a sound outside an empty room, which is much lower than listening to an outdoor sound with the door open. In fact, disruption of the auditory chain can cause deafness due to much more than suppurative otitis media, such as non-suppurative otitis media that can cause adhesions to the auditory bone, trauma that can fracture or dislocate the auditory bone, congenital malformation of the auditory bone or otosclerosis, all of which can manifest as hearing loss despite the presence or integrity of the tympanic membrane and conductive deafness on hearing tests.