Unilateral Hearing Loss

Unilateral hearing loss is hearing loss in one ear, with normal or near-normal hearing in the other ear. It ranges from mild to profound in degree. When hearing loss in one ear is severe to profound, the condition is often called single-sided deafness (SSD). Unilateral hearing loss affects a person's ability to localize sound (determine where sounds are coming from) and to understand speech clearly in noisy environments, as binaural hearing relies on the brain comparing input from both ears.

In children, unilateral hearing loss can affect academic performance, particularly in noisy classrooms, and may benefit from support such as preferential seating or an FM system. Management options include conventional hearing aids for milder degrees of loss, CROS (contralateral routing of signal) systems that route sound from the poor ear to the better ear, bone-anchored devices for single-sided deafness, and cochlear implantation in appropriate candidates.

In Canada, cochlear implantation for single-sided deafness is increasingly considered as evidence for its benefit grows.