Hundreds of people were in close proximity to the deafening bomb blasts at the Boston Marathon on Monday, and many have been treated at local hospitals for serious ear injuries. But hearing specialists say an untold number of other people could be suffering from hearing loss or ringing in their ears, called tinnitus, though they did not seek out medical help immediately.
Tufts Medical Center, which has treated a number of admitted patients for ear drum punctures and nerve damage, expects to eventually see outpatients with milder hearing problems, said Susan McDonald a senior audiologist at Tufts Medical Center.
Several patients visited Brigham and Women’s Hospital on Tuesday and Wednesday for hearing problems, as well as nonurgent shrapnel wounds. A spokeswoman said all had been discharged.
High-energy sound waves from an explosion can damage the ear by destroying nerve cells or ripping through the delicate eardrum tissue that separates the outer ear from the middle ear.
“Many of the patients with hearing loss that we’re treating were right by the bomb site, but it’s possible that less severe effects have occurred in those who were 100 feet or more away from the blast,” said Dr. Alicia Quesnel, an otologist at Massachusetts Eye and Ear, which has seen at least a dozen patients.
A 2004 Finnish study examining the effects of a mall bombing on hearing loss found that some kind of ear injury was likely for anyone standing up to 230 feet from the explosion, but it’s not known whether the size of that blast was similar to the one from the Boston bombs.
Mass. Eye and Ear posted a message on its website alerting people who were near the blast to seek medical attention if they are experiencing any signs of a torn eardrum. These symptoms include blood or other drainage from the ear, hearing loss, dizziness, and facial drooping.
Small holes in the eardrum usually heal on their own, but people with larger perforations may require surgery to restore hearing. Irreversible nerve damage leading to permanent hearing loss can sometimes occur from loud noises, though it’s usually more common from prolonged exposure.
“Some of our patients may have more severe nerve-related hearing loss that won't get better,” Quesnel said, and may require the use of a hearing aid. Since injuries can take weeks or months to heal, the extent of permanent damage will not be known for some time, she added.
A British study examining 12 patients who suffered ear injuries in a 1992 bomb blast on the London Bridge found that the three who had ear drum tears still had signs of hearing loss three years later.
Tinnitus can occur alongside these injuries as well as on its own. Described by many sufferers as a persistent pulse beat, whooshing sound, or high-pitched ring, the condition is thought to result from damage to sound-detecting hair cells in the inner ear and is known to occur frequently in people near bomb blasts.
The Finnish researchers found that two-thirds of 29 patients who were treated for ear injuries after the mall bombing had tinnitus and that many also had hearing loss, pain in their ears, and sound distortion. Of the nine patients who developed tinnitus without ear drum injuries in the British bombing, seven found that the ringing in their ears had stopped by four weeks.
While tinnitus that results from exposure to a loud explosion is usually temporary, it can sometimes last for weeks, months, or even years — and does not have a cure.
“Steroid drugs are a possible treatment, but it’s controversial because studies conflict on whether the drugs are actually helpful,” Quesnel said. Some patients try white noise machines or music to distract the brain from the inner sounds.
Hearing aids and relaxation treatments may also help bring some relief, according to the American Tinnitus Association.
Those near the Marathon blasts who are experiencing tinnitus do not necessarily require medical treatment if they have no other symptoms, Quesnel said.
“If they are experiencing severe hearing loss, they should see a doctor immediately, but if the tinnitus is mild and seems to be getting better, I’d give it a few days to see if it resolves on its own.”Deborah Kotz can be reached at firstname.lastname@example.org. Follow her on Twitter @debkotz2. Chelsea Conaboy of the Globe staff contributed to this report.