Definately
turntable
If it is an audio-output jack, then yes. If it is input, it can be used for a microphone. You can test this by trying headphones or speakers on the jack, this won't damage anything on your...computer?
The most common used audio input device is the webcam
That would be where you connect anything with a STEREO AUDIO OUTPUT.
Headphones meant for mobile phones will work for Personal Computers if tghey use the same input (The jack must fit into the audio in hole)
This is easy.... plug the input of the headphones into the headphone jack on the 'puter.
yes most sound cards have an audio-in input. Just look on the back of your computer, right next to where you have your current speakers plugged in there should be another input for an audio cable.
If they are for hearing then its output device as they are not putting anything in to the computer, if they have a microphone attached as well then they are input/output (i.e. microphone is input, speakers are output)
Speakers and Headphones are output devices. A microphone, sometimes integrated with speakers, is an input device.
Headphones are output devices.
headphones are output but if they have a built in mic then they either must be plugged into the microphone slot on a computer or are able to be plugged into USB which allows back and forth data transfer. Some like the apple earphones have a built in mic which allows the user to input audio data in the one predominantly output slot due to its specific construction. I'm not sure but this ability may be available on other newer devices. Source: Tinkerer and Maker of Things
Sounds like you have something plugged into the auxiliary input on your VCR that's putting the other audio into your recording.