cleaning

Okay, how does one clean a sample? Whilst getting feed back from my critique thread, I was recommended to EQ and clean my samples. What is this and how can it help? Also how do I go about EQ'ing the voice bank? I use audacity just to let you guys know. Please help!

When it comes to cleaning samples, there seems to be one side saying that it's best left untouched while there's another side saying that cleaning improves the quality but then again it seems to depend case by case. I record using my smartphone (a Samsung Galaxy V). Here's a sample. Would it...