Remote works BUT NOT THE VOICE COMMANDS

I haven't gotten a straight answer from anyone/anywhere. We went thru every option to reset and replaced the remote, worked for a minute maybe. If everything works but the voice command, the instructions don't make any sense. If I can change channels, up/down volume, etc. then what is the issue? When you speak into the remote, it doesn't understand us! What is listening, the box or the remote? How are the instructions being sent to the box and then to the TV? Is the box suddenly too old or our T.V. suddenly too old?  Has there been updates that have caused this issue. Can someone give me a straight answer, preferably from Comcast.