For people with hearing loss, the sound signals from the inner ear to the brain will be weaker than normal, and it's possible that the brain amplifies these signals too much to compensate, resulting in hypersensitivity. However, this doesn't explain the cause in those with hyperacusis and no hearing loss.
Bicycle Valve Stem Types. There are three types of bicycle valve stems in use: Schrader, Presta and Woods/Dunlop. The Woods or Dunlop valve stem style is much more rare than the other two. Any wheel rim that fits a Schrader valve can also fit a Woods or Presta valve.
What is a Valve Stem? The valve stem is a small, tube that protrudes from the tir eand is most often made of metal and rubber. The most common type of valve stem used in passenger vehicles is the Schrader valve. These are rubber valve stems with a metal tip that is threaded like a crew for the valve cap. These valve stems are also used on bicycles and motorcycles, though the construction materials may differ.