"Sound" is to "mute" as "visuals" is to what verb?
I would go with hide, if the context is content being played on a device.
- "The video is hidden, but I can still hear the audio."
- "The audio is muted, but I can still see the video."
To blind (out) or blank (out) come to mind.
I would suggest black out.
- The sound was muted and the visuals were blacked out.