I kind of know what you mean, but I've received great reviews for my voice demos. Even though there does seem to be someone that repeatedly blams it sometimes though. My score usually stays at about 4 but every once and while it drops down to 3.90 or something because of someone. Idk, whatever.
But it's been downloaded a few times (not much because who wants someone's voice demo?)
I think it was looked at pretty fairly. idk what type of voice acting you're posting, but if it's radioplays or podcasts or just things you think are funny, I don't think they're being "mistreated" they're just not widely accepted in the audio portal. It's for music, I just put my demo up so newgrounders could hear me, but other than that sort of thing, it's not a good place for that.
This is a flash website, ya know? There's just a lot of talented composers in the audio portal and they don't care about skits recorded and stuff.
for the most part, I think things are judged fairly.