Only 'voices in your head'?

Next time you hear voices in your head, it might not only be your imagination: It may be hypersonic sound targeted at you.

A note published in a newspaper reports the development of a new technology, called hypersonic sound, that allows to send sound messages in open places (e.g. a mall, the streets, a park, etc) to a specific recipient. The interesting part is that only such intended recipient will hear the sound or message; the people around won't hear it. The trick is that sound waves are sent at a very low pitch, which can't be perceived by the human hear. The waves restore their normal pitch when crashing an object, or a person.

This concept sounds partly cool, partly frightening. As some groups advocate and fear, this can be used by marketers to flood target audiences with advertisements and other undesired messages, effectively invading people's privacy. But on the other hand, it might have other useful applications, such as in certain types of alarms intended for only a specific person or group of people.

Although the development and application of this technology in a wider sense looks to be coming in a few years, the idea (and the results of the first tests) are already being controversial. Hopefully, this kind of technology can be used for really useful purposes, and not only to flood people with marketing campaigns.

Click here to read the whole note from the Times Colonist