Did Drugs Cause Limbaugh's Hearing Loss?

N E W   Y O R K, Oct. 13 -- While radio giant Rush Limbaugh tries to beat his pain killer addiction in a rehab clinic, questions about what really caused his hearing loss in recent years persist.

Questions have risen about the autoimmune inner ear disease that caused Limbaugh profound deafness between October of 2001 and January of 2002. The radio host subsequently regained hearing through the use of cochlear implants.

Research has shown that the drugs seem to sabotage the workings of the inner ear, causing permanent damage. But the drugs do not appear to affect the cochlear nerve, which brings sound into the brain.

Limbaugh's cochlear implant doctor, Dr. Jennifer Derebery, an otolaryngologist at the House Ear Clinic in Los Angeles, says it is possible that there is a connection between Limbaugh's sudden hearing loss and pill abuse, but she said there is no way to know for sure.

"We don't know why some people, but apparently not most, who take large doses may lose their hearing," Derebery said on ABCNEWS' Good Morning America. "The reason we don't know is that because we ultimately have to have biopsy specimens of the inner ear to tell that. but you can't biopsy the inner ear of a person who is alive because we are going to destroy the hearing," she said.

If the cause of the deafness were painkiller abuse, his treatment still would have been the same, said Derebery said. The only way he would be able to hear again is through the use of a cochlear implant, she said.

Road to Recovery

Limbaugh just finished his first weekend in a drug rehabilitation clinic, and he will spend the next 27 days fighting to beat his pain pill addiction once and for all.

After that, the conservative radio host will face the long struggle to rebuild his credibility in the wake of the stunning on-air confession he made to his 20 million fans Friday.

"I am addicted to prescription pain medication," Limbaugh said on his nationally syndicated radio show. "I first started taking prescription painkillers some years ago when my doctor prescribed them to treat post-surgical pain following spinal surgery.