November 3,2008: Continuing a century long trend, an increasing number of military personnel are suffering hearing loss because, well, wars, and military operations in general, are getting louder. While about 60 percent of troops wounded in Iraq had undiagnosed brain injuries (from all the roadside bombs), a large number also have ear damage as well. About ten percent of troops who have served there, whether wounded or not, are collecting disability payments for ear damage or hearing loss.

Since World War I, and the first large scale use of artillery, mortars and grenades, combat veterans have complained of long term hearing problems. This has led to more effort to develop electronic ear protection, that can allow troops to hear normally, when sound levels are normal, but block out very loud noises. Equipment like this is already available for those who maintain jet engines, and other loud equipment (like tanks). But making this gear rugged enough, and cheap enough, for everyone, will take a few more years, and perhaps longer. That's because some new equipment, like the powerful jet engines of the F-18E, F-35 and F-22, are so loud that the noise goes right through the head and damages the delicate tissues that enable us to hear. It's going to take a while for evolution to catch up with this one, although acoustic engineers believe they will come up with a solution in the next decade.

Meanwhile, there are earplugs available that will lessen the damage of very loud noises, and are rugged enough to survive battlefield use. The problem is getting the troops to wear them. Like loud music, many "ordinary" sounds of combat are ignored, but they gradually harm your hearing. It's the cumulative effect of more automatic weapons, and smart bombs. The latter are a problem because the improved accuracy allows the friendly troops to be closer to the target (the better to rush in an take care of armed survivors), where they get some of the loud noise from the explosion. Vehicles are getting louder because they use larger engines. Bases are noisier because of all the generators, and the troops often block out the "noise" with their iPods and video games.

The military has seen the problem coming. Back in the 1990s, when the U.S. Army developed a realistic M-1 tank simulator (a replica of the crew compartment, hooked up to a computer that generated realistic images on the sensors, and noises), the EPA (Environmental Protection Agency) insisted that the realistic engine noises be toned down, because they exceeded the noise level permissible at a workplace. While the military can ignore the EPA when training, or in combat, with the actual equipment, they had to comply with EPA rules when it came to simulators.