No Audio IVR Playback

Quite simply seen a few similar issues in the community, unfortunately there has been no definite solution. Dialing from an extension (7777) all works fine, once I dial into the SIP trunk (from an external line as should be) there’s no audio on the IVR, DTMF works so i can select the options - timing it manually - (but no Audio), Sound files checked and several used including the inbuilt GSM files as a test (still no audio) seen where it was suggested to modify (Answer() ) because of the ringing possibility, changed permissions on the folder for asterisk - From the debug and verbose the files show they are playing so the log wouldnt show any issues… Asterisk 11 + FreePBX + Centos 6.