the Soundpoint Ip 550 Desktop Phone Features Polycom's Revolutionary Hd Voice Technology, Which Brings Life-like Richness And Clarity To Every Call.1,5 Polycom Hd Voice Technology Incorporates Wideband Audio For Over Twice The Voice Clarity; Polycom's Patented Acoustic Clarity Technology For Crystal-clear, Noise- And Echo-free Sound, Plus Best-in-class System Design For High-fidelity, Faithful Voice Reproduction.