(CNSNews.com) - The cause of hearing loss for popular talk show host Rush Limbaugh may remain unknown and permanent, say medical experts.
Limbaugh revealed on Oct. 8 that he has suffered significant hearing loss since late May and is now completely deaf in one ear and has lost 80 percent of his hearing in the other ear. He did not say what his doctors believe is the cause.
"There are a few things that can cause it, and very often when they don't know what it is, a virus is blamed," said Kathy Harvey, a Virginia Beach audiologist and immediate past president of the International Hearing Society. Audiologists are hearing specialists who study hearing defects and their treatment.
According to Solveig Ingersoll, an audiologist who runs the Hearing and Speech Center in Maryland, sudden hearing loss like Limbaugh's can be caused by any number of things, such as a growth on the auditory nerve; cholesterol clogging blood vessels; a rupture in the inner ear that causes fluid leakage; autoimmune disorders or a virus (like mumps).
Ingersoll, however, believes that in Limbaugh's case, the cause is unlikely to be a tumor-like growth (because both ears are affected) or an inner ear rupture (because his hearing would fluctuate more).
"In many of [the cases], what you're doing is you're ruling out [possibilities]," said Ingersoll. "So you get MRIs (magnetic resonance imaging), you get CAT scans, you get blood work."
"Sudden hearing loss is usually related to some kind of trauma," Harvey explained.
"It can be a medical issue, maybe a stroke or a viral infection," she said, "[or] it can be a trauma such as being in an explosion or firing a pistol or rifle without protection.
While Limbaugh has worn headphones for many years as part of his job, that would be unlikely to cause a sudden hearing loss, according to Harvey.
Unfortunately for people afflicted with sudden hearing loss, accurate diagnosis and effective treatment are unlikely, according to Harvey.
For one thing, she said, the areas in the ear and brain that affect hearing are small and hard to work with.
Also, "there are just so many things that can happen," said Harvey. "If you had a sudden hearing loss after firing a shot gun, then the assumption could be made-but only the assumption-that the noise caused the trauma [and] the loss.
"It takes the person who does a lot of investigating as a physician or a specialist to pinpoint what happened," said Harvey.
"We have people who wake up in the morning, and they have no hearing in one ear," said Harvey. "Or they come out of the shower and they think there's water in their ear. They say their hearing just went.
"It's very, very rare, and I've been doing this for 26 years, working with the hearing impaired. It's very rare to reverse it," said Harvey.
Knowing the cause may not even make a difference, according to Harvey.
"Fortunately or unfortunately, the treatment is often the same," regardless of the cause, said Harvey. "If there's going to be a treatment that's going to work, they know just to hit it with steroids, anti-oxidants, a combination of drugs. These things are done even if you're not sure what caused it."
As to whether or not hearing loss can be at least arrested, "it would really depend on how quickly someone got to" a patient, she said.