Install jackmeter by entering the following commands in the terminal:
sudo apt update sudo apt install jackmeter
Description:
a basic command line meter for the JACK audio system
Jack Meter is a command line audio meter for the JACK audio system. This allows the user to check signal levels on remote computers without the need for graphical systems.
Homepage: http://www.aelius.com/njh/jackmeter/
Version: 0.4-1build2
Section: universe/sound