You can try adding an entry to /etc/pulse/default.pa to add echo canceling to your input selections.
As sudo, in any text editor open up /etc/pulse/default.pa (I am using vi).
sudo vi /etc/pulse/default.pa
At the end of the file (on its own line) add the line:
load-module module-echo-cancel
Save the file and exit.
In a terminal restart pulseaudio:
type pulseaudio -k
If there is doubt it restarted, you can check the process ID to see if it changes after you kill it. I usually just pkill pulseaudio
because I can never remember the command.... Or if there is doubt, you could restart your machine (overkill). But the pulseaudio -k command should kill the current pulseaudio process and restart pulseaudio... I only mention because I have wrestled with pulseaudio numerous times
Go to Settings ---> Sound (the graphical menu)...OR "Sound Settings..." if you're using a desktop with a panel(the speaker icon)...
On your "Input" section, you should now have an additional microphone selection with echo cancelling in your dropdown. Select that one as your input.