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.
Whatâs a presta valve? The valve on the right is a Schrader valve. The Schrader valve is the same valve thatâs used on car tires. So a bicycle tube with the Schrader valve can be pumped up at your local gas station if no hand pump (or CO2 cartridge) is available. The presta valve is on the left. This is typically found in bicycle tubes on many road bikes and some mountain bikes.