Is it possible to control the volume on the mame Simulator?

I am currently enjoying metal slug on my pc thanks to the MAME32 simulator, but I also want to play my music on the same pc simultaneously, but I can't seem to find where in the settings I can control the volume for games. Is this even possible?

Solution 1:

Way back then on Mame32 0.106:

• Options menu
• Default Game Options
• Sound tab
• Volume Attenuation slider, pull towards the left to reduce volume.

This would apply to all games.

Within games, volume down/up should be keys "-" and "=" by default, but it's not working for me. I'll update if I find out why.

Solution 2:

I use the tilde (²) key, European keyboard, ingame. Arrows left or right then decrease or increase volume.