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.
A saddle valve is mounted directly on to a pipe which is usually 1/2 inch copper tubing. Saddle valves are self-tapping devices. Once mounted on a line, with the included rubber seal in place, all that is required is to turn the valve clockwise until it pierces the water line. When the valve handle can no longer be turned, it is done tapping the pipe.