Listen To Your Ears. Hearing protection should never be ignored. EP7 Sonic Defenders Ultra earplugs protect your hearing against Noise Induced Hearing Loss (NIHL) without interfering with your ability to hear routine sounds or conversations. Their foam-tipped stem design, featuring soft memory-foam Comply™ Canal Tips, fits most people and provides a Noise Reduction Rating (NRR) of 28 dB. Sounds, at safe levels, are allowed to pass through into the ear canal, while potentially harmful noises (above 85 dB) are reduced via a proprietary design that incorporates a special noise-reducing filter. EP7s include attached filter caps, which can be inserted for additional protection and blocking out lower-level noise in situations where hearing ambient sounds or conversations isn't critical. They also serve as earpieces for compatible radio communication systems.