Sudden Onset Hearing Loss

Sudden Onset Hearing Loss is treated with the highest priority within the NSHSC audiology department. The amount of improvement may be related to how quickly the client seeks medical attention.

Sudden hearing loss (SHL) can be defined as greater than 30 dB hearing loss, over at least three consecutive frequencies (between 250 and 8000 Hz on the audiogram or hearing test), occurring over the course of 72 hours (3 days) or less.

About one third of people with SHL awaken in the morning with a hearing loss.

Sudden hearing loss can affect both the children and adults. It occurs most often in the 30 to 60 year age group and affects men and women equally.

SHL most often appears in one ear and is often accompanied by ringing in the ear, dizziness or both. The amount of hearing loss may vary from mild to severe, and may involve different parts of the hearing frequency range. SHL may be temporary or permanent. If you are dizzy, please have a family member or friend drive you to your hearing test appointment.

It is rare for a specific cause to be identified.

Booking Procedure

If a sudden loss occurred within the past 72 hours (3 days), a hearing test will be scheduled, if possible, within one working day of the clinic receiving the referral. If an audiologist is unavailable, the client/referral source should be referred to another site or a private practice audiologist.

What tests will I have?

The audiologist will ask you some questions about your hearing loss and your medical history.

You will then have a standard hearing test which includes:

  1. Pure tone audiogram (hearing tests with beeps)
  2. Middle ear testing with reflexes
  3. Otoacoustic emissions (OAEs – a test of the inner ear)
  4. Speech testing

The testing will take about 30 minutes.

If time permits, auditory brainstem testing which tests how the inner ear, hearing nerve and brainstem send the hearing information to the brain may be completed. This test can take about 20-30 minutes to complete.


Report will be written immediately and faxed to your family doctor. For those cases where the audiologist has the family physicians approval to refer to ENT, such a referral will be made immediately.

Follow up:

Follow up may occur with the Ear Nose and Throat Doctor (ENT).

We suggest a repeat hearing test 10 days post incident or when any medication your doctor has given you is complete, and then again at 3 months. 

If a permanent hearing loss is the result, your audiologist will make suggestions in keeping with the degree of loss.