Also note that a speaker can be used as microphones as well. (In physics terms they are the same device, which can convert sound to electricity or vice versa.)

Also note that a speaker can be used as microphones as well. (In physics terms they are the same device, which can convert sound to electricity or vice versa.) With modern sound cards having reprogrammable inputs and outputs, I wouldn't be surprised if even a laptop with no microphone installed could record audio. (My friend once had to record herself for a foreign language homework, but her microphone broke. I instructed her to plug her headphones into the microphone jack and ust them instead. It worked, but she had to talk loudly to make them work.)