load-module module-echo-cancel aec_args="analog_gain_control=0 digital_gain_control=0"
+
in the file:
/etc/pulse/daemon.conf
or
~/.config/pulse/daemon.conf
Uncomment the line, and set to no:
flat-volumes = no
load-module module-echo-cancel source_name=logitechsource
and then at the bottom of the file add
set-default-source logitechsource
In this case I named the source logitechsource, but you can name it whatever you want and simply either restart pulseaudio.
Y. Tabet, and M. Boughazi. Proceedings of the 7th International Workshop on Systems, Signal Processing and their Applications (WOSSPA), page 67-70. (May 2011)