Why foam earplugs can make your ears ache

Shoving dense polyurethane foam deep into your ear canal is a desperate act of sonic defense. To block out engine noise, you have to compress the foam, insert it, and wait for it to slowly expand to match the exact shape of your ear. This expansion naturally puts continuous, uncomfortable pressure on the delicate walls of your ear canal, forcing you to choose between throbbing pain or listening to screaming toddlers.