Rehovot-based Silentium has implemented silencing technology that reduces the noise of data centre computers, air-conditioning systems and even cooker hoods by up to 90%. Silentium’s “anti-noise” signal destroys the original sound wave and cancels out the noise. It reduces stress and heat and saves money.
http://www.timesofisrael.com/israeli-company-lets-you-live-the-digital-life-on-the-qt/
http://www.youtube.com/watch?feature=player_embedded&v=4ExBkpLJmpM