Visit msnbc.com for breaking news, world news, and news about the economyCheck out this gallery for a sampling of videos of what makes dogs howl. As you can see, it's a lot more than the Law and Order theme. A viewer writes:
Dogs are responding to the beat of the music. Not the drum beat, but the interaction between the musical notes from the selection of instruments playing both high and low frequency sounds. These beat frequencies produce something that is called the "missing fundamental effect" or "subjective tones" in the dogs. That is why it works regardless of the fidelity of the recording.
After the jump, a small experiment you can try at home.
The viewer continues:
You want to hear things? Play this very simple waveform by copying this text: sin(pi*t*5)*cos(3*pi*t)
...then plugging it into this audio beat simulator. (Be sure to unclick "Mute")
What do you hear? Does it look like the waveform that is playing? You hear the high frequency "dolphin" or "dj scratching" or "balloon twisting" or "zipper" sound? It is all subjective. Keep in mind the frequencies playing are quite low.
So, combining all the complex interactions of the instruments, the digital recording, and the dog's ear triggers a response that is akin to a howl.
If you try this experiment, let us know how your dog reacts.