It is off topic but I thaught its interesting.

http://infotech.indiatimes.com/articleshow/1087411.cms

And now, a soundless sound system


PORTLAND (OREGON): Elwood "Woody" Norris pointed a metal frequency emitter at one of perhaps 30 people who had come to see his invention. The emitter – an aluminum square – was hooked up by a wire to a CD player. Norris switched on the CD player.

"There's no speaker, but when I point this pad at you, you will hear the waterfall," said the 63-year-old Californian.
And one by one, each person in the audience did, and smiled widely.

Norris' HyperSonic Sound system has won him an award coveted by inventors – the $500,000 annual Lemelson-MIT Prize. It works by sending a focussed beam of sound above the range of human hearing.
When it lands on you, it seems like sound is coming from inside your head.

Norris said the uses for the technology could come in handy – in cars, in the airport or at home.

"Imagine your wife wants to watch television and you want to read a book, like the intellectual you are," he said to the crowd. "Imagine you are a lifeguard or a coach and you want to yell at someone, he'll be the only one to hear you."

Norris holds 47 US patents, including one for a digital handheld recorder and another for a hands-free headset. He said the digital recorder made him an inventor for life.

"That sold for $5 million," Norris laughed. "That really made me want to be an inventor."

He demonstrated the sound system at the Oregon Museum of Science and Industry, also called OMSI, recently.

Norris began tinkering as an inventor at a young age – taking apart the family radio and putting it back together again. He said ideas come to him when he's driving around or talking with friends.

"I don't know how I got to be an inventor, but I guess some kids can play the piano, and I can invent." Norris will receive the Lemelson-MIT Prize at a ceremony here.

One of his most recent patents is for the AirScooter, a personal flying machine designed for commuting. It reaches speeds up to 55 mph and is light enough – under 300 pounds – to not require a licence to fly.

The AirScooter was also on display at OMSI, although Norris didn't fly it.

The machine has a single seat, a four-stroke engine and is barely 10 feet tall. Its pontoons allow it to land on water. The machine's fiberglass and aluminum construction keeps its weight down. Bike-style handle bars move two helicopter blades, which spin in opposite directions.

Norris' AirScooter was shown on 60 Minutes last Sunday. He said since the airing of the show, more than seven million people have visited the AirScooter's Website.

Norris said he and his crew have tested the AirScooter for four years, and he couldn't have created the machine without a skilled group of aeronautics engineers around him.