I have had my Satellite L775D for a few months now and have never had a problem up until a couple days ago when it started making thiese really high pitched sounds coming from the speakers. It sounds like the external mic is on but i have no clue how to turn it off or stop the sounds besides muting the entire sound systerm. Please help me!
The next thing to do is make sure you're not "listening to" the microphone. Right-click on the speaker icon in the notification area near the clock and select "Recording devices." Right-click on your microphone (it should have a green checkmark - try clapping and watching the meter to determine which is the microphone in question if there are multiple) and select "Properties." Click the "Listen" tab. Ensure "Listen to this device" is NOT checked.