Hi ProfAnita,
Only just revisited this post so not sure if it's still relevant to you ... but, the code I was using also had audio (which I didn't post because mine was silent). I can post it if helpful, so that you can take out the bits that apply to you. Alternatively, I ended up using a relay switch to trigger a DVD player when the viewer passed a sensor. It was a bit clumsy for my installation (since there was a symbol from the DVD player that appeared in the projection whenever the switch was triggered), but since yours is purely audio, this might be a good workaround for you.