(photo by Mass Communication Specialist Seaman Alexandra Snow) Lt. Cmdr. Arnaldo Rivera, chief of the Ear, Nose, and Throat (ENT) Clinic at the National Naval Medical Center, checks Marine Lance Cpl. Josh Masterson’s ears during a pre-operative exam. Masterson underwent tympanoplasty surgery in August to correct his hearing loss. The procedure is helping wounded warriors who have experienced hearing loss after sustaining combat trauma.

In June, while serving in Afghanistan in support of Operation Enduring Freedom (OEF), Henderson suffered substantial injuries to both of his eardrums, cranial fractures and lost a leg after an improvised explosive device (IED) detonated near him.

‘‘When I first got injured, I couldn’t hear anything out of my left ear, and in my right ear it sounded like I was at the bottom of a swimming pool,” said Henderson.

He estimates 40 percent of his hearing was lost in the explosion. Physicians informed him that along with a small perforation in his right eardrum, his left eardrum is 60 percent destroyed, he said.

‘‘The hardest part of not hearing is trying to have a conversation with people [and] trying to watch TV,” said Henderson.

Lt. Cmdr. Arnaldo Rivera, chief of the Ear, Nose, and Throat (ENT) Clinic at the National Naval Medical Center, said Henderson’s experiences are similar to those of other wounded warriors he has treated.

Rivera has performed more than 20 tympanoplasty surgeries to correct hearing loss wounded service members have experienced.

‘‘Tympanoplasty is any surgery related to the ear canal, the tympanic membrane or the middle ear space,” said Rivera.

When a sound is made, the energy from the source of the sound moves particles in the air, stimulating the eardrum and transfusing energy into the brain’s sensors, which is then perceived as sound. People suffering from eardrum damage do not receive the same quality of vibrations from sound; therefore, have a harder time recognizing sounds below a certain decibel, said Rivera.

‘‘Loudness is a measure of energy or intensity and we measure that in decibels. Most people talk at about 50 decibels. [MP3 players] can play up to approximately 100 decibels,” added Rivera. The sound produced by a jet engine clocks in at 120 decibels, while a single IED blast can generate noise up to 170 decibels, according to the National Institute of Occupational Safety and Health (NIOSH).

To repair damage caused by exposure to noise of this magnitude, tympanoplasty involves making a small incision behind the ear and placing a stent in the damaged part of the canal, which is then packed with a dissolving sponge material, said Rivera, who currently has a 100 percent success rate with the procedure.

There is little discomfort associated with the surgery, he said, although it can take up to two months for recipients of the procedure to experience full results while the sponge completely dissolves. Once the gauze is fully absorbed, patients can expect hearing that is entirely restored.

Fully repaired hearing is what Marine Lance Cpl. Josh Masterson, an NNMC patient, hopes to get out of the tympanoplasty procedure he has scheduled later this month. Masterson was also injured by an IED blast in Afghanistan last year while serving in support of Operation Enduring Freedom. He currently suffers from perforation of the left eardrum.

‘‘Take a cup and put it over your ear and then try to speak,” said Masterson. ‘‘That ‘wah, wah, wah’ you hear, like Charlie Brown’s teacher in the cartoon, is exactly what it sounds like [to suffer hearing loss].”

‘‘It’s horrible to not be able to hear where noises are coming from,” added Masterson.

For patients like Henderson and Masterson, tympanoplasty offers hope.

Marine Lance Cpl. Brett Dawson, an infantry mortarman and NNMC patient, received the surgery in July and August to repair perforations in both of his eardrums. Dawson, who also served in support of OEF, sustained hearing loss after he was injured by an IED blast in April.

Although he is still in the healing process, his hearing has improved tremendously because of the procedure, said Dawson.

‘‘Before the surgery, talking to people and being in a crowd was hard. There was constant ringing in my ears,” said Dawson. ‘‘Now, I can talk on a cell phone, which I couldn’t do before ... I wouldn’t say [my hearing is] at 100 percent yet, but I can hear a lot better.”

Rivera said the patients are exactly why doctors who perform tympanoplasty surgeries come to work every day.

‘‘We’re very privileged to be able to help these guys,” Rivera added. ‘‘Their senses are being destroyed, but we can give them something back.”