<unk>  is hearing loss that is not associated with other signs and symptoms. In contrast, syndromic deafness involves hearing loss that occurs with abnormalities in other parts of the body. Genetic changes are related to the following types of<unk> . * DFNA:<unk> , autosomal dominant * DFNB:<unk> , autosomal recessive * DFNX:<unk> , X-linked *<unk> , mitochondrial Each type is numbered in the order in which it was described. For example, DFNA1 was the first described autosomal dominant type of<unk> . Mitochondrial<unk>  involves changes to the small amount of DNA found in mitochondria, the energy-producing centers within cells. Most forms of<unk>  are associated with permanent hearing loss caused by damage to structures in the inner ear. The inner ear consists of three parts: a snail-shaped structure called the cochlea that helps process sound, nerves that send information from the cochlea to the brain, and structures involved with balance. Loss of hearing caused by changes in the inner ear is called sensorineural deafness. Hearing loss that results from changes in the middle ear is called conductive hearing loss. The middle ear contains three tiny bones that help transfer sound from the eardrum to the inner ear. Some forms of<unk>  involve changes in both the inner ear and the middle ear; this combination is called mixed hearing loss. The severity of hearing loss varies and can change over time. It can affect one ear (unilateral) or both ears (bilateral). Degrees of hearing loss range from mild (difficulty understanding soft speech) to profound (inability to hear even very loud noises). The loss may be stable, or it may progress as a person gets older. Particular types of<unk>  often show distinctive patterns of hearing loss. For example, the loss may be more pronounced at high, middle, or low tones.
Nonsyndromic deafness
Cortical deafness
Post-lingual deafness
Prelingual deafness
Hearing loss with craniofacial syndromes
Surface dyslexia
Infantile esotropia
Vibroacoustic disease