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.
Schrader valve components (from left to right) the valve core closed (top) and open (bottom), the order of assembly, end view of stem without core and with core (top) and stem with dust cap on (bottom). Unusually tall Schrader valve stem with valve core. A Schrader valve advertisement in the journal Horseless Age, 1918.chrader valves are used in a wide variety of compressed gas and pressurized liquid applications. Presta valve stems are 6 mm diameter, whereas Schrader valve stems for bicycle tires are 8 mm, thus requiring a larger diameter hole in a bicycle rim.