ROBERT SIEGEL, HOST:
In the aftermath of the Boston bombings, we reported extensively on the deaths and the injuries that they inflicted. Well, there was another physical trauma, not as visible as the others, which was suffered by many people. Hearing loss, it was suffered by some people who were close to the blasts, others possibly 100 feet away or more. There was also an online video from a different explosion last week, the fertilizer plant in West, Texas, that gives a very vivid illustration of how delicate the eardrum can be.
This is a clip of Derrick Hurtt and his 12-year-old daughter Khloey. They were sitting in a pickup truck near the plant right before the explosion.
(SOUNDBITE OF VIDEO)
SIEGEL: I can't hear. I can't hear. And we should add that Hurtt and his daughter are both safe and her hearing returned, we gather, fully.
And to talk to us more about hearing loss injuries and explosions is Dr. Alicia Quesnel, who's an ear specialist at the Massachusetts Eye and Ear Infirmary in Boston. Welcome to the program.
DR. ALICIA QUESNEL: Thank you.
SIEGEL: And, Dr. Quesnel, you treated some patients on the day of the Boston Marathon bombings. What kind of hearing loss injuries did you see?
QUESNEL: Well, we did. We saw quite a few patients. The injuries that we saw really ranged from some minor trauma to the outside part of the ear, all the way up to patients who had, unfortunately, suffered holes in the eardrums or tears in the eardrums that occurred as a part of these blasts. The severity of the injury and the hearing loss that is incurred from this is really dependent on how close the person was to the blasts at the time. And certainly, some of these patients suffered both what we would call a mechanical hearing loss as well as, occasionally, some patients have suffered some nerve-related hearing loss as well.
SIEGEL: And when you say mechanical hearing loss, what do you mean by that?
QUESNEL: Well, mechanical hearing loss has to do with an injury to the ear that involves either the outer ear canal, the eardrum itself, or three ossicles, which are small bones that need to vibrate to transmit hearing into the inner ear. And so, damage to any one of those structures could result in a mechanical hearing loss.
SIEGEL: Is it evident whether the hearing loss is potentially a permanent hearing loss? Do you know that right away that it's just likely to be passing?
QUESNEL: Well, we can get an idea of that. The video that you showed is something that we would call a temporary threshold shift. So that's a temporary hearing loss that occurs in result to a very loud sound. Those will resolve over a period of time, which can be variable either within a couple of hours or a couple of minutes or sometimes a couple of days.
Whether or not it's going to be permanent or not, we can actually tell based on some bedside testing using an old-fashioned tool called a tuning fork. And also, we can get more detail on that for patients who are able to undergo a formal hearing test called an audiogram to be able to tell them what the prognosis is.
SIEGEL: When hearing returns after that kind of temporary loss, what's happening inside our ears that is bouncing back to normal after our loss of hearing?
QUESNEL: Well, there's actually been some acoustic trauma to the inner ear itself. An organ called the cochlea, which is the organ that translates sound energy into nerve impulses that go back to the brain to give us hearing, so some of the cells within that ear - that inner ear organ called the organ of Corti have actually been damaged temporarily.
SIEGEL: And they have the capacity to repair themselves?
QUESNEL: They do. If the trauma is big enough, however, then it can result in death of some of those cells or further disruption in the mechanics of the organ of Corti, which can then, unfortunately, lead to some cases of permanent hearing loss.
SIEGEL: You know, it must add to the chaos, which is bad enough already, of an explosion - a very near one - that so many people near it are at that moment experiencing at least a temporary deafness.
QUESNEL: That's certainly the case. If you look back at some of those pictures, you know, many of the pictures show that people are holding their hands over their ears. They clearly have had some trauma to their ears or hearing at the time. And I'm sure that does add to the chaos in an awful moment like that.
SIEGEL: Well, Dr. Quesnel, thank you very much for talking with us today.
QUESNEL: It was my pleasure. Thanks for having me.
SIEGEL: That's Dr. Alicia Quesnel of the Massachusetts Eye and Ear Infirmary, Transcript provided by NPR, Copyright NPR.