Sudden sensorineural hearing loss ("sudden deafness")
A rapid loss of hearing, happening all at once or over a period of up to 3 days. The hearing loss is often accompanied by dizziness or tinnitus and usually affects only one ear. Some patients recover completely without medical intervention, often within the first 3 days, sometimes it takes 1 to 2 weeks.

Ménière's Disease
Syndrome with various fluctuating symptoms: vertigo or strong dizziness, tinnitus, hearing loss and the sensation of pressure or pain in the affected ear. Ménière's Disease usually breaks out suddenly, affects most often only one ear, and can arise daily or as infrequently as once a year. Typically, the attack is characterized by a combination of vertigo, tinnitus and hearing loss lasting several hours, with frequencies, durations and intensities of the discomforts varying from patient to patient. Periodic attacks of vertigo (or dizziness) are the most disruptive symptom to the patient. It occurs in the form of a series of attacks over a period of weeks or months and produces nystagamus, nausea, vomiting, sweating and all the symptoms usually associated with extreme motion sickness. Hearing tends to recover between attacks, but over time it becomes worse. Overall, Ménière's Disease is a progressive disease.

Autoimmune inner ear disease (AIED)
An unusual form of progressive hearing loss and / or dizziness, which occurs over a period of weeks to months. Its symptoms are sudden hearing loss in one ear progressing rapidly to the second ear. Patients may also feel fullness in the ear and experience vertigo, and some kind of tinnitus may also be experienced.

Further disorders like infections of the inner ear (labyrinthitis and neuronitis), acoustic neuroma (a slow-growing tumour), auditory neuropathy, etc.