I have a Toshiba laptop and up until recently I have had no problems. However after playing music I heard an awful screeching noise.
Now I find that if the speakers volume setting is low it aoppears fine but when I take the volume a little higher [to the half way point] a terrible screeching nows is heard.
I don't know if I have played the musioc too loud and damaged the speakers - but surely this would occur at all volumes wouldn't it? or if it is either a hardware or software fault. Somebody suggested that I may need to download knew drivers and tnhat may resolve the problem.
When the speakers screech tap the top of the lid where the web camera/mic is and if you can here the tapping through the speakers the mic is on, or lower the lid when it is not screeching and if it starts screeching confirms mic on.