When a person has lost total ability to hear in one ear, it is referred to as single-sided deafness, often called unilateral hearing loss. The other ear is typically not affected in patients with single-sided deafness, but they commonly have trouble determining the direction from which a sound is coming, especially in noisy environments. Although hearing cannot be restored, several devices can be fitted by an audiologist to help channel sounds to the good ear.
Single-sided hearing loss can be caused by several conditions and sometimes appears suddenly. An accident that causes head trauma might result in deafness on the corresponding side of the head. Ear infections or tumors in the ear or brain can also lead to single-sided deafness in some people. Meniere's disease, which cannot be prevented, has been linked to hearing loss in adult men and women.
A person suffering from single-sided deafness usually tries to compensate by using his or her good ear in social situations. This can be difficult if several people are talking at the same time, or other background noise is present. He or she often cannot separate speech from other noise in order to hold a meaningful conversation. Single-sided deafness is also troublesome for pedestrians if they cannot distinguish the direction of traffic. While driving, it can impair a motorist's ability to determine the source of sirens, horns, or other warning sounds.
In some cases of single-sided deafness, no cause is ever found. Sometimes, if the hearing loss is sudden, partial or total hearing may return in a few weeks. When an ear infection exists, hearing may be restored when the infection is cured. Tumors are treated with surgery, if possible, in an effort to reverse single-sided deafness.
Several devices can be worn to help direct sound to the ear that is not affected. The most common is the contra-lateral route of signal (CROS Aid) device that uses a wire to direct sound from the bad ear to the good ear. Digital, analog, and wireless models exist, along with features that are programmable to reduce background noise. These aids commonly produce an annoying tinny sound or vibration in the good ear that outweighs the benefits for some users.
Meniere's disease provokes ringing in the ears, dizziness, and loss of balance. The attacks come on without warning and sometimes result in ear pain or pressure. The more frequent the attacks, the greater the risk of hearing loss. Medication is typically used to treat vertigo or nausea associated with the disease, but the cause of the condition is not known. It may be connected with stress, and relaxation techniques have been used successfully in some patients to reduce the duration of attacks.
