Sometimes you don't want survey participants to see each other's comments.
Comments for comment-enabled questions are public by default. To change this setting, click the comment question's gear icon. (You can also do this when initially setting up the question.)
Scroll down past advanced options:
and click Private.
As a survey administrator, you'll still be able to see private comments, but this will hide them from public view.
Note: If comments were set to private initially, you won't be able to make any existing private comments public any time after you change this setting. This is by design to ensure participants who wish to submit their comments privately can do so without fear of those comments being made public.
Can I moderate comments?
How comment moderation works
Comment admin options and actions