[10dpd]

Don't do this - the best way to evaluate is to compare the visual output with the auditory output, something you can't do if the screen is turned off.

[elbrian]

The two practices are not mutually exclusive. Why not test against both?

[throwaway857384]

I sort of agree, from my experience, I know what to expect when I see something, so seeing and hearing helps me quickly spot the issue.