Sudden Deafness can be amazingly frustrating.. .. .. What is sudden deafness? Sudden sensorineural (“inner ear”) hearing loss (SSHL), commonly known as sudden deafness, is an unexplained, rapid loss of hearing either all at once or over a few days. SSHL happens because there is something wrong with the sensory organs of the inner ear. Sudden deafness frequently affects only one ear. People with SSHL often discover the hearing loss upon waking up in the morning. Others first notice it when they try to use the deafened ear, such as when they use a phone. Still others notice a loud, alarming “pop” just before their hearing disappears.