4s speaker damaged

Today I dropped the corner of my 4s into some acrylic paint. I've cleaned it but I think some seeped through the holes. At normal volumes it sounds ok but when I put in on max it sounds horrible- crackly and distorted. I compared it to an iphone 5 and that didn't have any alteration to the sound at high volumes. So is this how a 4s operates at high volumes? Shall i get it repaired and how much will apple charge?