Unfortunately, freesound (like any other sound/music related service I know) - does not develops pragmatic comment system (...and does not have tools to allow users to create such one).
What do I mean by "pragmatic comments".
Well - let say that you are beta testing something. Or doing a research on something. Or gathering brain-storming creative thoughts for your marketing routine. Or creating a fan-list. What types of comments do you need? What questions/topics should be answered/touched and in which way? What kind of questionnaires should be there, and how to organize them in order to get valuable questions? It's like this. "Did you liked? [Yes / No / Don't know / Don't ask]" - this one brings nothing particular. But if you start like "What did you liked in that sound?" or "Which aspects of that sound you did not liked and why?" and give some hints or selectable options, then you get comments you need/expect. So it's somewhere between giving the space and giving directions. Without directions - listeners are usually lost, and can express themselves strangely sometimes. 
BTW, freesound is somewhat research oriented project, so think about how to raise the level in tat particular area.
Well to get rid of comments inclusive double posts that happens time and time again, why not do a facebook X button to delete ones comments that has been double posted? I succeeded today:
http://www.freesound.org/people/miastodzwiekow/sounds/123039/
jobro wrote:
... why not do a facebook X button to delete ones comments that has been double posted?
When I login there is a cross icon on the right of each comment on my samples which will delete the comment if clicked on.
Timbre wrote:jobro wrote:
... why not do a facebook X button to delete ones comments that has been double posted?When I login there is a cross icon on the right of each comment on my samples which will delete the comment if clicked on.
I think he might be talking about deleting his own comments on other users samples. It doesn't look possible to me.