No sound from speakers

[kcv250]

Evening all
The car (2003 XKR) has decided that the soundtrack from the exhaust is all I need to hear and isn't providing any sound from the speakers on either the radio or CD player but the in built car phone still works perfectly. Radio and CD player appear to be working, if I leave the CD playing it changes track at the end, the radio displays and changes stations and the volume change is displayed.
Has any body experienced this and can help before I start taking the car to bits.
Any help or advice gratefully received.
Keith