Most people just stick them in halfway. Properly seated plugs are the difference between quiet and wasted effort.I worked over 20 years in a can plant (an extremely noisy environment) properly used foam ear plugs can be VERY effective. You must roll them between your fingers to get them small enough to put them deeply into your ears then hold them there until they expand (4 or 5 seconds) There is a learning curve, but once you get the hang of it, they can be very good.