No sound during Bravo and E shows, just during commercials

I have reviewed the posting on this issue and none of them work. Bravo and E go to commercial and when they come back there is no audio. We got no help from COX. We replaced the Vizio TV with a $2,000 Sony, same problem. We replaced the set top module today, same problem. Have not replaced the Modem, but that would be the second modem in 6 months. Also, the reset from Cox did not affect this problem.