Plantronics is no stranger to LR given that we have reviewed many of their Bluetooth headsets over the years.  This time around, we are taking a look at the Plantronics .Audio 476 DSP which is a USB 2.0 powered headset.  The Plantronics .Audio 476 DSP headset is a foldable stereo headset just announced in January 2010 during CES, that offers digital signal processing to enhance the sound quality. The noise cancelling microphone uses a wideband acoustic echo cancellation to get natural sounding voice audio.