Sudden sensorineural hearing loss (SSHL), commonly known as sudden deafness, occurs as an unexplained, rapid loss of hearing—usually in one ear—either at once or over several days. It should be considered a medical emergency. Anyone who experiences SSHL should visit a doctor immediately.
Sometimes, people with SSHL put off seeing a doctor because they think their hearing loss is due to allergies, a sinus infection, earwax plugging the ear canal, or other common conditions. However, delaying SHHL diagnosis and treatment may decrease the effectiveness of treatment.