Install volumecontrol.app by entering the following commands in the terminal:
sudo apt update sudo apt install volumecontrol.app
Description:
Audio mixer for GNUstep
VolumeControl is a GNUstep program for adjusting the audio mixer on systems that use the ALSA or OSS APIs. It allows the sound level, left/right speakers, muting for master, PCM, bass, and treble levels to be controlled.
Homepage: https://github.com/alexmyczko/VolumeControl.app
Version: 0.6-1build2
Section: universe/sound