An ear infection may sometimes cause a temporary or reversible hearing loss. This generally occurs because the infection blocks sound from passing through the ear canal or middle ear to the inner ear. When sound is blocked like this, it is known as conductive hearing loss. You may hear sounds as muffled or indistinct.
Types of infection that may cause temporary or reversible hearing loss include:
Inflammation or infection of the ear canal (otitis externa). This condition is often referred to as "swimmer's ear," though too much water in the ear is not the only cause. Inflammation, swelling, or buildup (exudate) in the ear canal may block sound from moving to the middle ear. Hearing usually returns on its own after the infection goes away. Middle ear infection (otitis media). Swelling and pus may block sound from moving to the inner ear. Hearing usually returns on its own after the infection goes away. Untreated middle ear infections may cause permanent damage to the structures of the middle ear that results in permanent hearing loss. But this is rare. Most ear infections get better on their own, but sometimes antibiotics may be needed. And few ear infections cause permanent damage. Fluid in the space behind the eardrum (otitis media with effusion). This may occur with or without infection. Fluid buildup may distort sound or block its passage to the inner ear. Fluid behind the eardrum usually clears on its own, although the eardrum may burst if the fluid in the middle ear becomes infected. Viral infection of the cochlea (the main sensory organ of hearing). This causes sudden hearing loss. The viruses that cause this type of hearing loss are thought to be the same ones that cause upper respiratory infections such as influenza or a cold. Hearing may not return, may partially return, or may completely return.