How Do You Read Earplug NRR and Attenuation Ratings?
Shop for earplugs and you'll immediately meet an alphabet of ratings: NRR on one package, a decibel figure like "20 dB" on another, and attenuation charts on manufacturer spec sheets. These numbers describe different things, and knowing how to read them makes comparing products much less confusing. This page explains the terminology — for guidance on what level of protection you need, the right person to ask is an audiologist or other hearing professional.
What the NRR is
The noise reduction rating (NRR) is the single decibel figure you'll see on hearing-protector packaging sold in the United States. It summarizes how much a protector reduces sound: a higher NRR means more reduction. The NIDCD's overview of hearing protectors describes the main types of protectors — foam plugs, pre-molded plugs, earmuffs, and musician earplugs among them — and is a good starting point for understanding what these devices are designed to do.
Two things keep the NRR from being the whole story for a musician. First, it's a summary number, and it says nothing about which sounds are reduced more than others — which matters enormously when the "noise" is music you're trying to play in tune with. Second, the rating assumes the protector is worn correctly.
Fit changes everything
A protector only delivers its rated reduction when it's inserted or seated properly. A foam plug rolled tight and placed well into the ear canal behaves very differently from the same plug perched loosely at the entrance. Both the NIDCD and consumer guidance from ASHA on noise and hearing loss prevention emphasize proper fit and consistent use when choosing and wearing protection. Practically, this means the number on the box is a ceiling, not a promise, and it's one reason two players using the same plugs can report very different experiences.
Flat attenuation: the musician's spec
Ordinary foam plugs tend to muffle high frequencies more than low ones, which is why music through them sounds dull and why it gets hard to hear your own intonation and your section's blend. Musician earplugs are designed instead for flat (even) attenuation — reducing loud sound while keeping the balance across frequencies closer to natural. For example, Etymotic specifies its ER20XS high-fidelity earplugs as reducing sound by about 20 dB evenly across the frequency range, which is a much more modest reduction than many foam plugs advertise, traded for fidelity.
So when you compare a foam plug against a musician plug, you're not comparing like with like: one is optimized for maximum reduction, the other for usable reduction. Our page on musician earplugs vs. foam earplugs goes deeper into that trade-off.
Reading a manufacturer's spec sheet
Beyond the headline number, manufacturer spec pages often show attenuation at specific frequencies — how many decibels of reduction at low, middle, and high pitches. Here's how to read that information:
- A flat line across frequencies means the plug reduces bass, midrange, and treble by roughly the same amount — the "high-fidelity" behavior musicians want.
- A line that climbs at high frequencies means treble is cut more than bass — typical of foam, and the source of that underwater sound.
- The stated decibel figure (like the ER20XS's roughly 20 dB) tells you the overall depth of reduction; flat-attenuation plugs generally advertise lower numbers than foam plugs do.
Ratings in the rehearsal room
How loud your seat actually is depends on the hall, the repertoire, and who's behind you — a chair in front of the trumpets is a different environment from the back of the second violins. Standards and safety bodies have written specifically about music settings: the NASM–PAMA advisories on hearing health address musicians directly, and both are worth reading alongside any spec sheet. For a broader look at the options themselves, start with our overview of hearing protectors for musicians.