Like others, the microphone on my HTC One M7 is patchy. I can hear people fine, but they say I'm echoey, far away, quiet. It seems to have become worse too. I believe it might be to do with the noise cancelling mic as mentioned here although I don't know why it would be deteriorating if that's the case.
I don't have root access or I could try this fix.
Apart from the root fix or the old toothbrush fix, is there anything else I can try?
Keen to keep my nice old HTC. Currently running 5.0.2.