Power off the iPhone
Remove the case and any screen protector edges near the speaker grilles
Use a soft, dry, clean, anti-static brush to gently brush the speaker grilles
Hold the iPhone with the speaker opening facing downward while brushing
Tap the iPhone lightly against your palm to dislodge loose debris
Use a clean, dry cotton swab to lift dust from the grille edges
Use painter’s tape or low-tack adhesive tape to pick up surface lint
Use compressed air only if necessary, with short bursts from a distance
Avoid inserting pins, needles, toothpicks, or metal tools into the grille
Avoid liquids, cleaning sprays, and wet cloths on the speaker openings
Repeat the cleaning gently until debris is removed
Test the speaker with audio at low volume
If sound remains muffled, contact Apple Support or an authorized service provider