Try the following:
# Check that the muting function on the TV or speakers is turned off. Also check that the volume is at the appropriate level.
# If an audio device is connected, check the settings of the device. For details, refer to the instructions supplied with the audio device.
# There may be a problem with the cable. Try using another cable that is compatible with the PS3 computer entertainment system.
# Some software does not support digital audio output.
# If the PS3 system's audio output settings do not match the cable or device in use, the system may not produce sound. Check that the system's audio output settings are correct.
If none of the above helps call Sony at 1-800-345-7669 !