If you are having issues hearing audio, or are getting a black screen instead of your VR content when using an Oculus Rift or Rift S headset you will need to manually update your Oculus drivers.
Follow this guidance to manually update your Oculus drivers.
Start by fully disconnecting the headset from your computer and close the Oculus app.
Open This PC from the Start bar
Open the OS (C:) Drive
Click on Program Files
Click on Oculus
Click on Support
Click on oculus-drivers
Click on oculus-driver
If prompted, allow Oculus to make changes to your computer
This will open and run the Oculus driver and update the software automatically for you.
A progress wheel will appear for a short time. Once this has disappeared, the update is complete
Reconnect your headset and launch the VR content to check the audio or visual issue has been rectified
Here is a video taking you through those steps: