I go 4 fingers down from the collar on the front, and just under the front collar impression on the backside of the shirt. everyones fingers are different so I measured mine and the 4 fingers measure 3.5. I also use my left hand to guage where to put left chest logos.
Grey noise then, has a sound frequency that, if translated to a light frequency, would roughly be the color grey. Grey noise is a random sound that is distinguishable from other types of sound because it sounds the same, to the human ear, at all frequencies.
How Noise-canceling Headphones Work. Bose was the first company to introduce noise-canceling headphones. See more pictures of essential gadgets. One man's noise is another man's music, but no matter what your taste, ambient noise is the enemy. Luckily, there's a piece of audio equipment designed especially to maximize your listening experience, keeping ambient noise out without sacrificing your music's sound quality.