Infrasonic sound can have very unusual non-auditory effects on the body. But does it kill?
There’s an elevator in the Brown University Biomed building (hopefully fixed by now) that I’ve heard called “the elevator to hell,” not because of destination but because there is a bent blade in the overhead fan. The elevator is typical of older models, a box 2 meters by 2 meters by 3 meters with requisite buzzing fluorescent, making it a perfect resonator for low-frequency sounds. As soon as the doors close, you don’t really hear anything different, but you can feel your ears (and body, if you’re not wearing a coat) pulsing about four times per second. Even going only two floors can leave you pretty nauseated. The fan isn’t particularly powerful, but the damage to one of the blades just happens to change the air flow at a rate that is matched by the dimensions of the car. This is the basis of what is called vibroacoustic syndrome—the effect of infrasonic output not on your hearing but on the various fluid-filled parts of your body.
For the rest of the story: http://www.popsci.com/technology/article/2012-11/acoustic-weapons-book-excerpt