Speakerphone is full duplex analog conference phone, allowing simultaneous two-way communication. Speakerphone comes with three built-in omnidirectional microphones and can be expanded with two more microphones. Echo and noise cancellation, provided by the patented SoundClear Digital Signal Processing (DSP) chip, delivers unprecedented clarity of sound. Speakerphone has expandable modules to conform to digital, PBX systems, and to add Bluetooth compatibility. Design also includes buttons for redial, flash, conference and hold.