Input Aec Block - Extron electronics DMP 128 FlexPlus User Manual

Input AEC Block

About AEC
Echo occurs when audio from a talker in the far end is received and amplified into the near
end listener's room, with that sound then being picked up by microphones in the near end
acoustic space and sent back to the far end. The amount of signal sent back to the far end
talker can be substantial, and with the added transmission delay, the result is an echo effect
that can seriously compromise communication in a teleconference or videoconference.
The Extron Acoustic Echo Cancellation (AEC) processor removes the potential echo
signal at the near end mic channel by comparing it to the received signal from the far end,
designated as the "reference," and then creating an adaptive filter to cancel the potential
echo before it is sent back to the far end.
Successful operation of the AEC processing block is mainly a function of proper gain
structure and selection of an AEC reference. This section provides an overview of those two
elements.
Proper gain structure involves the relationship between the signal at the selected reference
and the signal at the mic input, within the context of proper levels for the reference and mic
inputs independently. The mic input gain setting will naturally be optimized for the voice level
of the talker in that room. Therefore, the amount of signal from the far end picked up by the
mic is dependent on how much far end signal is being amplified in the near end room and
the distance from the mic to the speakers.
AEC Operation
Double-click the block to open the drop-down menu. Select to insert the AEC
AEC AEC AEC
processor.
Figure 46. AEC Block and Drop-Down Menu
NOTE: Insert the AEC processor on the input with the near end microphone connected.
Once the AEC processor is inserted, double-click the block to open the dialog box.
AEC AEC
DMP 128 FlexPlus • DSP Configurator Software 27