Foam looks soft, but it's basically a sponge. It expands unevenly, gets itchy and damp on a long flight, and goes gummy after a few uses. And about 30 minutes after you finally fall asleep, you're patting the seat for it, or finding it on the floor.
Hears Sleep isn't foam. It's built with DeepSeal Blend: silicone and TPE layered together for a denser seal than a standard single-layer tip.
Nothing to squeeze flat, nothing to wear out, and it moves with you when you toss and turn. So it doesn't fall out, doesn't hurt, and you don't wake up confused. Just a distant hum you can actually fall asleep to, snore, cabin drone or road noise. Not "quieter." Quiet.