Is Human inaudible machinery possible?

today morning, my friend called me over phone, but he was completely inaudible to me bcos there was a heavy machine running beside me. I knew that human ear cannot decipher sound beyond 22kHz (20-22KHz audible range). So, I just wondered if its possible that we can make machinery that will scream only beyond 22 KHz , so that humans hear nothing and we get rid of the noise pollution that's all around the city you live on the names of cars, heavy machinery, construction machinery oooh, if something of that sort is a possibility, I wonder how enormous the effect would be on the world. Being a telecommunication engineering masters student, I am not sure...but just a thought and wouldn't like to pass...so wrote it out here...

Praveenjothi
Darmstadt
04th July 2005

Posted byPraveen J at 8:45 AM 0 comments