I have been interested in silent dog whistles all my life. But since I don't hunt animals with my dog, I didn't see the need for one. Still, I've always been curious about how the dog whistle works. For example, I wondered if it was really "silent"...

When my husband and I stopped at a pet shop the other day, I finally succumbed to my curiosity and bought the cheapest silent dog whistle at the store. I got very excited and immediately opened the package and tried blowing the whistle. My first impression was that the whistle isn't really "silent", though of course it doesn't produce a loud sound like an ordinary whistle. At home, I tried blowing the whistle many times by adjusting the sound, while watching my dog's reaction. Her ears often perked up, but I couldn't tell if the dog was just reacting to the new gadget I got, or if she actually heard the sound that we humans can't detect. I went to another room and tried blowing the dog whistle, but I still couldn't tell.

Dogs can hear sounds that we humans can't. Dogs' hearing range is 40 to 46,000 Hz. The human hearing range is 20 to 20,000Hz. (Cats perceive frequencies from 100 to 32,000Hz. Bats and rodents can perceive frequencies up to 150,000Hz !).

Why do dogs hear high frequency sound? High frequency sounds travel farther than lower frequency sounds. One theory is that the ability to catch high frequency sounds (such as howling or the sounds of other animals) enable dogs (or wolves) to locate their own species or prey efficiently in the wild. In this sense, silent dog whistles make more sense than using your own voice (which is lower frequency) to call your dogs' attention from a long distance in the open field, especially in hunting where not speaking too loudly is important.

I tried the dog whistle again. This time I chose time when my dog was taking a nap. I asked my husband to watch the dog's reaction as I went to another room. I adjusted the whistle's frequency as I blew it for a while. When I came back to the room and asked my husband how the dog reacted. He said she didn't move an inch. I feel like I may have to be patient and keep practicing for a while, maybe in the open field next time...