Chosen Solution
I have this problem from 2 weeks ago , is it from Fan ?
Yeah that sounds like a fan to me. Take the back off and press on the center of the fan and see if it reseats. Also, at that time you can disconnect the fan and actually see if I am correct. MacBook Pro 15" Retina Display Mid 2012 Left Fan Replacement
Please check video which is explain the source of problem ( Fan)
It is probably from the speaker, as if the fan was doing that, the MacBook would probably overheat and shut off.
