It isn't aproblem per se. The MBP has pins for grounding IIRC and the one in the area you mentioned sometimes makes the noise you hear. There is an entire recent thread on this forum about it with photos and explanations. Don't worry about it is the general consensus from what I read.
https://forums.macrumors.com/threads/1662859/
Oh, and as for internal sound cards, pro, semi-pro, or consumer, don't EVER expect a three dollar internal sound chip to yield decent audio. Get a USB audio interface and you'll be in much better shape. There are hundreds to choose from for your usage.