by Dr. Gavin Setzen
It is not uncommon for us to notice occasional changes in our hearing from time to time. Most frequently, this has to do with benign, reversible issues. Occasionally, however, a sudden change in hearing may be secondary to an underlying phenomenon known as sudden sensorineural hearing loss (SSNHL), a process that needs to be treated quickly and definitively to increase the probability of hearing recovery.
There are several benign causes of sudden changes in hearing. The most common one is impaction of earwax in the ear canal. Everyone produces earwax in the ear canals, and contrary to popular opinion, earwax is not dirt or a sign of poor hygiene. In fact, earwax is a natural antibiotic, antifungal, protectant, and moisturizer of the ear canal. Unfortunately many people feel the need to use Q-tips in the ear canals, which is more likely to impact earwax deeper in the canal and cause a blockage of the ear canal. This will result in sudden changes in hearing which may worsen when water is allowed in the ear canal. Typically this is easily diagnosed by your physician on physical exam, and the wax can be removed with either irrigation or manual disimpaction, with immediate improvement in the hearing. Most people do not need manual cleanings of their ear canals in general, as the ears will clean themselves if left alone.
Another common cause of sudden changes in the hearing is trapping of fluid in the middle ear behind the eardrum. This is not uncommon during an upper respiratory infection or after a flight when the Eustachian tubes become inflamed and prevent the fluid that is naturally produced in the middle ear from draining. This results in a muffling and blockage sensation in one or both ears, and occasionally the sensation of fluid moving around in the ears with head movements. Allergies can also be implicated in this process which may cause lesser degrees of blockage sensation. These issues can also be diagnosed on physical exam and can often be confirmed with the use of tympanometry, a device that measures the pressure of the middle ear space. This will usually subside with the use of decongestants and nasal steroid sprays, but often can take several weeks to subside completely.
Infection of the ear canal or middle ear space is another common cause of a sudden change in hearing. This is typically accompanied by pain and possibly discharge from the ear, making these types of issues relatively easy to diagnose and treat. Fortunately, this hearing loss typically reverses once the infection is treated, but once again it can sometimes take weeks to completely recover.
A more concerning cause of a sudden change in hearing is SSNHL. This is considered a medical emergency. This represents a sudden change in the nerve function within the cells of the inner ear, and frequently causes permanent nerve damage in the affected ear. Sudden hearing loss is classified as a change in the hearing nerve function in the inner ear which occurs over a period of minutes to several days. The degree of hearing loss can range from mild all the way to severe. It typically happens in only one ear, but can happen in both in rare circumstances. Formal audiometric testing in a sound-proof environment is the mainstay of diagnosis of this phenomenon. This testing reveals a change in the ability to hear certain tones and recognize speech accurately. Typically normal middle ear pressure is noted with tympanometry. This phenomenon should be strongly suspected when a patient notices a sudden change in hearing but there are no abnormal findings on physical exam. Unfortunately, some people’s ears are difficult to examine because of the curvature of the ear canal, presence of obscuring earwax, or natural thickening of the tympanic membrane. It should be noted that one of the ways your doctor can differentiate conductive hearing loss from sudden sensorineural hearing loss in the acute setting is with the use of tuning fork testing, a simple test that can differentiate these 2 phenomenon. Unfortunately this test is frequently overlooked in the acute setting. As a result, some patients with SSNHL are diagnosed with "fluid" without having an audiogram or tuning fork testing, and are often erroneously treated with antibiotics and decongestants. It is only when the symptoms do not subside over several weeks that some patients are finally sent for formal audiometric testing in the true diagnosis is found.
It is not always clear what causes SSNHL. Some theoretical causes are viruses, tumors (usually benign), blockage of very small blood vessels of the inner ear, or membrane rupture of the inner ear. Because of damage being done to the inner ear, SSNHL can also be accompanied by a new sensation of ringing in the ear (tinnitus) or dizziness ranging from low grade to severe. For some people, the sudden change in hearing will return to normal without treatment. For others, the change in hearing is permanent regardless of treatment. Fortunately, if a patient is seen early enough after the onset of SSNHL, immediate intervention in the form of high-dose steroids such as prednisone can improve the chances that the hearing loss will recover. The longer the period of time between onset of the hearing loss and treatment, the less chance that any treatment will be able to reverse the hearing loss. Steroids can be taken by mouth over a period of 2 weeks, or can be directly injected into the middle ear (transtympanic therapy) in the office over several weeks. Some people may be candidates for hyperbaric oxygen therapy as well, especially if none of these measures are successful. Because of the risk of tumor causing sudden hearing loss, an MRI scan of the brain and inner ear with intravenous contrast is almost always recommended for workup. Depending on how the hearing stabilizes over time, patients are frequently candidates for a hearing aid or other surgical and nonsurgical interventions to make up for the loss of hearing.
The bottom line: If you notice a sudden change in your hearing, call your physician to be seen as soon as possible. If the cause of hearing loss is not immediately evident on physical exam and tuning fork testing, you should be referred for formal audiometric testing right away to determine the nature of the hearing loss and need for further workup or treatment.
At Albany ENT & Allergy Services, we have 7 ENT specialty physicians, 4 ENT specialty physician assistants, and 4 doctors of audiology who are able to immediately diagnose and treat patients with all different types of hearing loss.