Hi , I`m Jack and I will be helping you today
Please note that I am an independent tech. that depends on your positive rating to get paid by this website and I have no control over the phone (or other) offers , they are sent by the website ,not by me but let me know if you`d rather do this on the phone.
That being said , a few questions coming up and by the way , pearl that greeted you is a computer so never mind the odd questions and suggestions.;
The fact that you are on ATT tells me you have a cable box and
as cable boxes are known to cause sound problems , the first thing to try would be a reboot ;
Pull the cable box`s power cord off the wall outlet (cable box only) for a minute.
In the mean time turn off the tv and turn it back on only after you plug back the cable box power cord.
Note that it may take a couple of minutes for the cable box to reboot after you plug it back ,just give it time.
Let me know how that goes and please take the time to rate my answer positively (use the stars to rate) if that answers your question / does the trick as it is the only way i get paid for helping you , otherwise do not rate at all , just let me know and we`ll try something else.
Note that you can reach me here still at any time after rating if you have questions.