deafness
Our editors will review what you’ve submitted and determine whether to revise the article.
- Mayo Clinic - Hearing loss
- WebMd - Hearing Loss
- Patient - Deafness in Adults
- World Health Organisation - Deafness and Hearing loss
- The Nemours Foundation - For Teens - Hearing Impairment
- Centers for Disease Control and Prevention - Hearing Loss in Children
- Merck Manuals - Professional Version - Hearing Loss
deafness, partial or total inability to hear. The two principal types of deafness are conduction deafness and nerve deafness. In conduction deafness, there is interruption of the sound vibrations in their passage from the outer world to the nerve cells in the inner ear. The obstacle may be earwax that blocks the external auditory channel, or stapes fixation, which prevents the stapes (one of the minute bones in the middle ear) from transmitting sound vibrations to the inner ear. In nerve deafness, some defect in the sensory cells of the inner ear (e.g., their injury by excessive noise) or in the vestibulocochlear nerve prevents transmission of sound impulses from the inner ear to the auditory centre in the brain. Deafness at birth is nearly always of the nerve type and cannot be improved by medical means.