Generally, hearing will decline evenly in each ear over time, which is referred to as a symmetrical hearing loss. Asymmetrical hearing loss means the degree and configuration of the hearing loss are different in each ear (one ear hears worse than the other). No matter the degree of loss, asymmetrical hearing loss requires further evaluation and a referral to a physician specializing in disorders of the ear, nose and throat.
Possible causes of this type of loss can be something as simple as the patient spending a lot of time firing weapons; in that case the hearing loss usually is in the ear opposite the weapon. Often dentists will notice a similar loss from using a dental drill. Naturally, wearing ear plugs can go a long way in protecting your hearing in these scenarios.
Other causes of asymmetrical hearing loss can include:
• sudden idiopathic hearing loss (having no known cause)
• acoustic neuroma (a tumor of the vestibular nerve that gradually grows and compresses the cochlear nerve)
• meningioma (a tumor of the dura — a tough layer that covers the brain)
Also, Meniere’s syndrome, which usually manifests with a triad of symptoms including a fluctuating sensorineural hearing loss, vertigo and tinnitus, can contribute towards an asymmetrical hearing loss.
We as hearing healthcare professionals know hearing can be an indication of overall health, and sometimes an asymmetrical loss is the only symptom of an underlying health problem. We refer these patients to a physician and obtain medical clearance before proceeding with a hearing instrument fitting in the case of asymmetrical hearing loss.
If you ever experience sudden hearing loss in only one ear, seek professional help from your doctor immediately. Delaying could hinder the effectiveness your treatment.