It's not magic. It's not science fiction. How does sound frequency-to-ear/mind work? (&only 1 person hears it)

Question

Criminal Elements use this technique to drive their "targets" insane or to suicide. Please take the time to answer this question in simple terminology so us "non-tech" people can understand. thanks! (these sounds can be transmitted long distances) For an example of what I'm talking about: anyone remember the movie "Real Genius" with Val Kilmer? Remember what they did to the character Ken with God's voice? That's generally what I'm talking about, but more advanced technology.

Answer 1

Actually, I experimented with a technique many years ago to create sounds that only a single person can hear.

If you are familiar with “beat tones”, you will understand the concept. Have you ever heard two tones that are ~almost~ the same frequency, (Think of tuning a guitar, or riding in a plane with two props, or a boat with dual engines.) but are off enough that you hear this underlying beat?

Basically, when you combine two tones, your ear hears both tones AND the sum AND the difference between them. Let’s say you are tuning a guitar. One string is an A at 440Hz, and the other is a little off at 445Hz. Play them together and you hear the tones and the 5Hz (the difference between the two) tone that sounds like wah-WAH-wah-WAH…

OK, so take it up a notch. Take two sound sources, both ultrasonic beyond the range of human hearing. Let’s say one is 30kHz (that is 30,000Hz. The human ear can only hear up to about 20kHz) and the other is 30.06kHz (30, 60Hz)

Assuming that you have a parabolic or tubular transducer so the sound sources are directional, you set them up so they are pointing at a particular location. The trick is to have them so they are situated so the two sound beams meet at a 90 degree angle.

Let’s say we have one guy in a crowd that we want to annoy. Set one beam 50 feet away and pointed at the person. For this example, assume this beam is pointed NORTH. Set the second transmitter 50 feet away to the WEST of the target. Both transmitters are aimed at the target, and their beams are crossing at a 90 degree angle.

At that intersection point, whoever is standing there will hear an annoying 60Hz tone, which sounds like the hum from a powerline. There will be no direction to the noise, because the sound is actually coming from the interaction of two ultrasonic waveforms. The sound truly will sound like it is coming from inside the subject’s head.

Step outside of that intersecting area, and you hear nothing.

The width of the intersecting area depends on how tight the sound beams are, and how far away from the target the transmitters are.

Hope this helps!

It is real. I have done this experiment before.

Answer 2

Sounds like something only in a movie. There is no way to distinguish one person's ear from another without having some kind of receiver implanted into the recipients ear.

Answer 3

It's MOVIE magic. It IS science fiction. You can have highly directional microphones, but not the reverse.