High-fidelity earplugs use a small engineered acoustic filter to reduce volume fairly evenly across all frequencies, so sound gets quieter without losing clarity. Cheap foam plugs, by contrast, block sound unevenly and muffle the high frequencies, which is why music sounds dull and underwater through them. Understanding this difference is the whole point of buying a high-fidelity pair.
High-fidelity earplugs use a small engineered acoustic filter to reduce volume fairly evenly across all frequencies, so sound gets quieter without losing clarity. Cheap foam plugs, by contrast, block sound une