Noise Induced Hearing Loss

Sounds can be harmful when they are too loud

Sounds that are too loud, even for a brief time, or when they are both loud and long-lasting can be harmful. These sounds can damage sensitive structures in the inner ear and cause noise induced hearing loss (NIHL). 

NIHL can be immediate or it can be noticed after a long time. It may be temporary or permanent, and it can affect one or both ears.

What causes Noise induced Hearing Loss?

NIHL can be caused by a one-time exposure to an intense “impulse” sound, such as an explosion, or by continuous exposure to loud sounds over an extended period of time, such as noise generated in a working environment.

Your distance from the sound-source and the duration you are exposed to the sound are also important factors in protecting your hearing. A good rule is to avoid noises that are too loud, too close, or last too long.

What are the Symptoms of NIHL?

The main features are hearing loss and buzzing (tinnitus). The patient describes it as a “stuffy ear”. The hearing loss is usually mild to moderate and concerns the high frequencies in the 4000-6000Hz range. The buzzing (tinnitus) is located normally in one ear and is very intense in the first moments after the loud noise. It may be a temporary phenomenon, but it creates a problem if it becomes permanent. 

Very rarely, dizziness may occur as a complication indicating a rupture of the round or oval window of the ear or even greater hearing loss which may be due to a rupture of the tympanic membrane or a subsequent disruption of the auditory ossicles.

Diagnosis of Noise Induced Hearing Loss

If you have been exposed to a very loud noise or explosion, especially when it is accompanied by a reduction in hearing and buzzing you should contact your Otorhinolaryngologist. International guidelines recommend that this visit be done as soon as possible (within 48 hours) because early treatment is extremely important.

Hearing examination

Noise Induced Hearing loss Examination.

The otolaryngologist will assess your hearing using otoscopy, tympanometry, sound reflexes and both air and bone conduction audiograms.

Treatment

Cortisone is the cornerstone for the treatment of NIHL. It is administered orally or intravenously and is often combined with intratympanic administration (to increases the chances of success). Up to five intratympanic cortisone injections spaced 3-5 days apart are usually recommended. 

The prognosis is generally good if diagnosed and treated early.