I don't know exactly if this applies the same way because I have it on the retail version. The simple solution is remove any CD's while playing, but you could go into the options and click audio. Many options will appear, including one that says 'play CD music'. Uncheck it. I dont know if it'll be the same on steam, but that's how it works on retail. Hope I helped

I don't know exactly if this applies the same way because I have it on the retail version. The simple solution is remove any CD's while playing, but you could go into the options or configuration menu and click audio. Many options will appear, including one that says 'play CD music'. Uncheck it. I dont know if it'll be the same on steam, but that's how it works on retail. Hope I helped