ClearOne Chat 150 Speakerphone has Distributed Echo Cancellation® and noise cancellation along with full-duplex performance and automatic level controls guarantee your conference calls to be natural with unmatched audio clarity free of any distractions. First-mic priority intelligently activates only the microphone closest to the person speaking, preventing the amplification of ambient noise and room reflections. Daisy-chainable design can expand up to two complete speakerphones to cover medium-sized rooms. Full speakerphone expandability allows both mic and speaker to cover the entire room along with flexibility of control using any speakerphone.