In general terms, there are two types of hearing loss, conductive and sensorineural. A combination of both is also seen as a mixed hearing loss.
Conductive hearing loss is caused by any condition or disease that blocks or impedes the conveyance of sound through the middle ear. The result is a reduction in the sound intensity (loudness) that reaches the cochlea. Generally, the cause of conductive hearing loss can be treated with a complete or partial improvement in hearing.
Sensorineural hearing loss results from inner ear or auditory nerve dysfunction. Often, the cause cannot be determined. It is typically irreversible and permanent. It, too, reduces the intensity of sound, but it might also result in a lack of clarity even when sounds, particularly speech, are loud enough. The treatment for sensorineural hearing loss is amplification through hearing aids.
A mixed hearing loss is a combination of a conductive and a sensorineural hearing loss. Hearing aids can be beneficial for persons with a mixed hearing loss, but caution should be exercised.