Doggie Lullabies

Dog whistles have been around for a long time. They emit a note that is above the range of human hearing. One single, monotonous, boring note. Dogs can be trained to do a variety of stupid pet tricks upon hearing this whistle... I suspect that they do these tricks because they're hoping you'll stop blowing it.

Others have marketed doggie lullaby products such as [link]. but the problem is humans can still hear them. Why not play classic lullabies, many octaves higher than people can hear, over huge loudspeakers to all dogs in a 6 block radius, every night?

Now you can leave your window open again without having to hear the chorus of barking neighbor dogs. Window bars optional for low rent precincts.