The mic on my HTC one stop working mid conversation. Took it in my locall Vodafone shop and a member of staff there stuck a paper staple into the mic hole on the bottom of the phone and wiggled it about, he said it might be blocked. After a couple of attempts all seams to be back to normal. Then by the time I got home it had stopped working again. Checked on youtube found to video about mic faults and the first video said put some tape over the mic on the back of the phone to the right and above the camera lens. Tried this and all seems good now. But if you record a video the audio is very quiet.