1 Pixel density: Pixel density-The pixel density of a display represents the number of pixels over an area of one inch. 2  Itâs measured in âpixels per inchâ, or ppi.
Eustachian Tube Dysfunction can be caused by large adenoids, allergies, or a cold. This dysfunction can cause crackling or popping noises in our ears. The tube is lined with moist mucosa, and inflamed Eustachian tubes often get sticky, which causes the crackling and popping noises when the tubes are moving around. If the inflammation is serious, it can be easily treated with steroid nasal sprays.
Noise-Induced Hearing Loss. Noise-Induced Hearing Loss (NIHL) occurs when loud noise damages the working of the inner ear and causes hearing loss. It can be the result of a one-time exposure to an intense impulse sound, such as an explosion, or by continuous exposure to loud sounds over an extended period of time. Roughly 20% of adults in the US, about 48 million people, report some degree of hearing loss. At age 65, 1 out of 3 people have hearing loss. (1) According to the American Tinnitus Association, Noise-Induced Hearing Loss (NIHL) and tinnitus is currently the number one service connected disability of veterans returning from Iraq and Afghanistan.