Hello!

I suggest you open an LXTerminal and issue the following commands.
Code:
sudo apt-get update
sudo apt-get install pulseaudio pavucontrol
mkdir -p ~/.config/pulse
echo "autospawn=yes" > ~/.config/pulse/client.conf
echo "daemon-binary = /usr/bin/pulseaudio" >> ~/.config/pulse/client.conf
restartx
Use the PulseAudio volume control from the "Multimedia" menu to adjust settings.