You've may have inadvertently changed an audio setting somewhere. Here's how to check:The SAP (Secondary Audio Program) on your TV set may be turned on. To deactivate the SAP, look for a button on your TV remote that says "SAP," "MTS" or "Audio Mode." Turn it to the "off" position or follow any on-screen displays which tell you how to deactivate SAP. You may need to change the setting from SAP to "mono" or "stereo."
Consult your TV owner's manual or contact the place where you bought your TV if you have difficulty turning off the SAP channel. Most TV manuals are also available online. A search of the make and model number of your television will often get you a link to the user manual.
Once the SAP channel has been turned off, the proper audio track should return. Some TV's allow you to turn the SAP channel on for each of your TV channels individually.
If you have a digital-to-analog converter box connected to your TV, you may have changed the default setting in the box. You want to have the "Primary" or "First" audio service selected. Some boxes have an "Audio" button that allows the setting to be easily changed. Other boxes require you to make the change by finding the audio settings section within the on-screen menu. Restoring the Primary service should restore the correct audio.