User's Manual

9
Echo & Noise Cancellation
z DSP(Digital Signal Processor) integrated A1 eliminates echo and noise thereby
providing clear voice quality even under harsh environmental conditions.
z If A1 is used as ‘Car Handsfree’ mode in car, it eliminates surrounding noise
(engine noise, wind noise, surrounding noise, radio sound etc.) and delivers clear
voice to the other party. Also, it eliminates echo signals created by transmission of
car speaker sounds to the microphone. The above mechanism for echo and noise
cancellation is realized through the use of 2 microphone system and high-tech
algorithm which cancels out unnecessary noise and delivers only the user voice.
The directional microphones process only the user voice signal and therefore, for
best performance for use in car, mount the A1 onto sun visor.
z On the other hand, if A1 is used as ‘Speakerphone’ mode, it doesn’t matter in
which direction the A1 is placed as noise signals generated from all directions will
be processed thereby making it suitable for conference calls. However, it is
important to note that the performance of ‘Speakerphone’ mode can be slightly less
than ‘Car Handsfree’ mode.
z The transition from one mode to another and vice-versa takes place automatically.
That is, if A1 is placed upright, ‘Speakerphone’ mode will be activated and likewise,
if it is placed upside down, ‘Car Handsfree’ mode will be activated. However, this
automatic mode transition doesn’t take effect during talk mode.