How can i clean my microphone? Siri cant hear me and when on speaker people barely hear me and also when i record myself i cant hear anything just muffled

Well one day i decided to use siri to call my mother and she wouldnt respond. I thought it was cause if my poor connectio. But then i payed close attention and sae the wave wouldnt move when i talked. Well i thought it was a one time thing so i ignored it. Later on i recorded myself and noticed what i had recorded had no sound. I then noticed it was my microphone. I need help. How can i clean? Or how much will it cost for apple to repair?