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.
There are five types of valve stems: 1  Rising Stem with Outside Screw and Yoke. The exterior of the stem is threaded, while the portion of the stem in the valve is smooth. The stem threads are isolated from the flow medium by the stem packing.