While a DVR recording is in progress, the audio is muted.
Note: This issue only applies to customers who have the following On-Screen Guide:

Note: This issue only applies to customers who have the following On-Screen Guide:

Impact
Audio is muted while a DVR recording is in progress.
Steps to resolve issue
If you have lost audio during a DVR recording, you should manually restart your box by pressing and holding down the power button for 10-15 seconds then pressing it again to restart.
If you continue to experience issues, please visit our Discussion Forum Community from any Internet-connected device. Chances are, your question has already been asked and answered. If not, post your question and get answers from Comcast employees and/or customers like you.
Or, please Contact Us using the method that is most convenient for you - chat with us online or call us to speak with a Comcast representative.