Computers are different here. I now have a Dell Latitude 14" machine (I can't find the model number now... On older model the model number was printed over the keyboard, but it isn't anymore), and it came with two mic's built into the top of the display bezel, next to a reasonable web cam. With Skype and similar apps on Linux, the audio is really good.
My old machine (also a Latitude, but a 7-8 year old model) had the mic on the main body of the machine, above the keyboard. That meant it picked up all sort of keyboard and fan noises, making an external webcam with a built-in USB mic completely necessary for internet telephony.