Problems with Emerson EWC27T3 27 in. TV/VCR/DVD...

The picture is good on all channels but some (not all) channels have Spanish audio but only for some programs during some of the day. The same channels are in English later in the day.  Some channels have no sound at all.  Close caption is in English and is correct for the programs. Some commercials have audio for different commercials but some match the commercial being shown. English is set as the language and the audio is set to SAP.   I have cable service and other televisions in my home work correctly.  Please help.  I am tired of reading the captions watching this tv but it is the one set up in front of the treadmill in my garage.