Plantronics Blackwire C220m Headset Microsoft Office Communicator Digital Sound Noise Canceling Plantronics Blackwire C220M headset for Microsoft Office Communicator. Plantronics Blackwire C220M headset for Microsoft Office Communicator. Noise-canceling microphone limits outside noise, ensuring great audio quality and easing listener fatigue. Digital Signal Processing and wideband frequency optimizes audio for more natural voice quality. Hi-Fi audio with stereo sound optimizes music and video quality.