Before you use any solvents, take a clean, old soft toothbrush and gently scrub over the speaker ports. Its good to do this periodically because of lint and accumulations anyway. Normally the screen catches most debris, and the toothbrush will brush them out gently. Make sure it doesn’t have old, dried toothpaste residue, or you just exacerbate the issue. Compressed air may help, but don’t point it directly into the speaker as you can damage the diaphragm.