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sudo nano /etc/pulse/default.pa
Add this line at the end:
load-module module-echo-cancel
pulseaudio -k
Set input as default
If you wish to set as default the echo cancel device simply turn the above line into:
load-module module-echo-cancel source_name=NameOfYourDevice
and then at the bottom of the file add
set-default-source NameOfYourDevice
In this case I named the source logitechsource, but you can name it whatever you want and simply either restart pulseaudio.
Rename device
Lastly, if you do not want a super long name on the Sound Settings (When you want to select an input/output device). My suggestion is renaming the input device like this:
load-module module-echo-cancel source_name=logitechsource source_properties=device.description=LogitechHD
Source: https://askubuntu.com/questions/18958/realtime-noise-removal-with-pulseaudio//