A sound level higher than 85 decibels (football matches, fireworks and festivals) is harmful for young ears and could cause permanent hearing defects. Protect your little one’s hearing with the Reer SilentGuard Ear Defenders. Due to their insulation, these capsule ear defenders protectors have a single number rating (SNR) of 27. This SNR means that the protector reduces the sound intensity by 27 decibels before the sound reaches the eardrums.