When making a call your voice sounds muffled, quiet and/or distorted to the other caller.
Applies to: HTC Wildfire, HTC Desire, HTC Incredible (and no doubt many more)
On modern mobile phones the microphone is located inside the phone, leaving a tiny hole in the case to allow sound to travel from you to the microphone.
This hole is easily blocked by lint and dust from your pocket – affecting the quality of the sound it hears.
You can fix this problem using a drinking straw. Using scissors cut a pointed end and carefully insert the straw into the microphone hole few millimeters, rotate the straw and remove – you should see a small amount of dirt removed. Repeat as many times as necessary, making sure you do not push the dirt down into the hole or put pressure against the microphone inside the phone.