Distorted Audio on Microphone

I have a G3 that has been experiencing issues with the microphone. When you use it in handset mode the audio is distorted on calls. I dismantled it to investigate, thinking I might just need to replace the butterfly flex (Thinking G2)But, to my surprise there was no butterfly flex, and the mic is soldered directly to the board now. Being familiar with soldering Galaxy S3 Charge Ports I figured "Maybe the mic is lose?" This wasn't the case though. I tried backing up, and restoring the phone to see if this would solve the issue... but it did not. So, I can, with certainty rule out the possibility of it being a software bug.

Please, if anyone has any suggestions, do chime in.

-Cheers!