pasuspender is a tool that can be used to tell a local PulseAudio sound server to temporarily suspend access to the audio devices, to allow other applications access them directly. pasuspender will suspend access to the audio devices, fork a child process, and when the child process terminates, resume access again.

Make sure to include -- in your pasuspender command line before passing the subprocess command line (as shown above). Otherwise pasuspender itself might end up interpreting the command line switches and options you intended to pass to the subprocess.