Sound Defense Dog Deterrent Device

You could use a standard air horn to scare away aggressive dogs during a ride, but a small start-up company called Sound Defense says its patent-pending version is more effective. The higher tone it emits is based on a study that determined the pitch canine ears find most offensive. Humans can certainly hear the 105-decibel blast, but there's also a range that registers only on Fang and his partners in mayhem. The website has a "how it works" video showing the results during a ride near Houston. (No product photo is available; only a rough prototype was shown at Interbike.) The company is planning to sell the system with a bike mount for a yet-to-be-determined price and then provide replacement canisters. One will last for about 2 dozen 4-second blasts. If all goes to plan, Sound Defense says its product will reach the market next spring. http://www.sounddefenseonline.com