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.
PN59D8000 and JVC RS420 with Elite 120" screen
Receiver - Yamaha RX-A3060, WXA-50 MusicCast Amp for Zone 2
Front - CM9, Center - CMC2, Side Surrounds - DS3, Rear Surrounds - CM5, Front/Rear Atmos - CCM663, Subs - PB12+ and PB13 Ultra
Remote/Streaming Media Players - Harmony Elite, Apple TV 4, Nvidia Shield Pro - use with HDHomeRun Connect/Extend and Plex