Audio Spotlight

There was a lecture/seminar by Prof. Barry Vercoe in NUS today. It was organized by ACM SIGCHI Singapore and SCS SIG on Entertainment Computing and ECE. Basically, it was under the initiative to promote digital media in Singapore.

The nice thing was the who’s who interested in Media from NUS, NTU and Singapore was around. The best thing was that Prof. Vercoe was talking about his own research and the Media Lab at MIT.

The one that caught my attention was AudioSpotlight. I had known about it, but forgotten. There was some controversy about it, but the technology itself is cool..

The idea is to be able to direct the propagation of sound, instead of letting it spread in all directions, as speakers do. This allows you to have personal speakers, that can direct sound specifically towards a small area, using ultrasound. Ultrasound being very directional, can be ‘beamed’.

The idea behind is very simple, but difficult to explain. Audible sound modulated with an ultrasound carrier tends to demodulate itself in a certain pattern, as it propagates through the air. As to why this happens, I think it has something to do with the non-linearity in the relationship between pressure and particle velocity. So one can use this to ‘encode’ the audible sound so that the demodulation can yield itself back.

The uses of this are infinite. There are some listed on the website. Personally, I wait for the time when they can have one on every seat in the bus so that I can turn TVMobile off! At least for myself.