You don't need that fancy tools. An RGB camera with simple linear filters will give you an rPPG signal if you are stationary. And then you can trigger a sound from each detected top.

You can also buy cheap ppg readers that are very easy to use.

However: one defect by using PPG is that you will have a delay between heartbeat and signal due to the time for the blood to move.

Or you could work on the fear...