I would take a toothbrush with some rubbing alcohol and scrub the ear speaker mesh. If that doesn’t work you could take a sewing needle and gently !$$&* small holes across the ear speaker and see if that makes a difference. This problem is very common.
The best thing would be to take it into apple and get a top case replacement. This should be around $299-399. Otherwise local repair shops could probably find you a used one to do the same thing with.
Slide in a playing card to loosen the adhesive. If its warm enough it will easily slide off. Shouldn’t take experienced professionals more than an hour or so. Reapply a light layer of b700 and clamp.