My ps3 is in storage right now, so I can't tell you exactly, but I think what you might need to do is go into your ps3 audio settings and choose optical instead of hdmi. Then, assuming your AVR is set to the input for which you plugged your optical cable into (game, TV/Video, etc), you should have sound from your AVR and not your TV. If it's already setup that way and you're still not getting audio from your AVR, reply back.
Samsung TV - PN59D8000 - wall mounted
HW50ES projector w/electric Elite 120" ceiling mounted screen (drops in front of plasma)
Receiver - Yamaha RX-A3000
Front Speakers - B&W CM9, Center - B&W CMC2, Surrounds - B&W CM5
SVS PB12+, SVS PB13 Ultra