USB power for PC and Laptop LED will illuminate External power supply included for phone only configurations when Duet is not plugged into the PC 100% Full duplex performance – no attenuation either way during full duplex Acoustic echo cancellation 40 dB High end performance conforms to ITU T G.167 standard Line echo cancellation Noise cancellation 10dB Residual echo is suppressed to the environment noise level to prevent artificial ducking of signal Voice level equalization Convergence speed 40 dB/sec Tail length 200ms Convergence during full duplex no recovery time after full duplex Low delay 10 msec Bandwidth 20Hz – 16kHz for speech processing maintains the soundcard bandwidth Integrated loudspeaker Omnidirectional microphone pickup pattern 360 . Equal output or sensitivity at all angles Integrated loudspeaker Mute button and loudspeaker volume control buttons LED will blink in mute mode Four position gain setting for optimum adjustment of signal level into the telephone Speech processing and echo suppression at 32KHz sampling rate HD speaker audio 16KHz bandwidth Maintains audio performance of the PC for HiFi audio applications when external speakers are connected Plugging in a headset will automatically turn off the speakerphone USB connector – PC or Laptop connectivity and power 2.5mm connector 3.5mm connector Cable with 2.5mm and 3.5mm connections