First try re-reading the directions, then apply a fresh pair of earplugs, making sure your hands and ears are clean and dry. Moldable silicone earplugs are designed to stick to the surface of a clean, dry ear. If the earplugs are being used in a moist and/or dirty environment, be sure the hands and ears are clean and dry before applying or re-inserting the earplugs or a proper seal may not be achieved. A sign that you have achieved a proper seal is that your own voice will sound more internal and exaggerated. Lastly, try covering the ear canal with the earplug starting from the rear and moving toward the face. This technique squeezes out some of the air in the ear canal before sealing it shut, thus creating a bit of a suction effect. This last technique takes a little practice but creates an excellent seal when done correctly.