Invention 49: Dog Repeller

Once in a while, I put up what I believe would be viable and profitable inventions -- that I don't, however, have the time to (fully) develop. Now the loudest whistle in the world (pictured) is the Hyperwhistle. This is more than 140 decibels, or some 100 times louder than an ambulance siren. The loudest dog whistle is less than 110 decibels, which is, say, 50 times softer than an ambulance siren. The Hyperwhistle is not designed for dogs -- it has a frequency of about 3 kHz -- while dog whistles have a frequency of well over 20 kHz. I have both owned and designed electronic dog repellers -- in fact, one of my designs is on this blog: Dog Repeller. This uses a small ultrasonic transmitter (0.5"), which cannot be very loud if it could be heard by humans. Yet it scares dogs. Now the invention here is: take the non-electronic Hyperwhistle, push up the frequency ten times, and create a Hyperwhistle for dogs. Even if it is "only" 120 decibels, it will be as loud as an ambulance siren for humans. OBSERVATION: There may be one problem, however. It may be thought to be unethical to hurt dogs' ears. At the same time, as a minister having visited many homes, I know what it is like to be nipped and even bitten by aggressive dogs -- and that hurts humans! The same for postal workers. A dog repeller can help.