The name Etymotic means true to the ear. Etymotic’s products are used by scientists, hearing practitioners, hearing-impaired consumers, professional and amateur musicians, and others who insist on superior sound quality. Etymotic High-Definition Series Electronic Earplugs were developed to mitigate hearing damage and tinnitus sustained by an alarmingly high percentage of deployed soldiers. Despite risks to hearing from loud machinery and blasts, most warriors decline to wear hearing protection because they find it interferes with situational awareness. These earplugs are designed to restore sound that is blocked when the ear canal is sealed. They allow you to hear naturally, as though there were nothing in the ears, and prevent ear damage from loud impulse noise using a new adaptation of the original high-fidelity K-AMP integrated circuit. HD15 is for persons who operate some or most of the time around continuous loud noise such as machinery, trucks, or construction equipment and want both blast protection and natural hearing when no background noise is present. HD15 circuitry is configured with adaptive attenuation to become a 15-dB earplug when noise levels put the user at increased risk for hearing damage. This unique attribute protects the user in loud continuous noise from machinery and vehicles and from unexpected impulse noise such as gunfire and explosions. When no loud noise is present, the HD15 returns to natural hearing, as if nothing is in the ear to block sound. The HD15 also has a switch to boost faint sounds. Since 1983, Etymotic products have improved the lives of those with hearing loss, protected hearing, and enhanced the listening experience of musicians and music lovers everywhere.