The C520 microphones use dynamic noise reduction and adaptive feedback control to provide crystal clear HD audio transmission, even in crowded or spacious rooms. The microphones synchronize with the base station in real-time according to their location. This technology allows the user freedom of movement without even having to raise their voice – regardless of meeting room size. Snom HD Voice transmits sound via high-quality speakers while the inbuilt microphone provides crystal clear voice quality. G.722 wideband codec for crystal clear HD quality calls.