Pro Ears electronic hearing protectors use DLSC technology to compress the impulse sound from range fire to a safer level, as opposed to shutting down the system. While compressing the impulse sound wave the system also amplifies the lower level sounds such as voice, allowing for continuous operation. Pro Ears' Pro Tac Gold hearing protection has an NRR rating of 33 and large ear cups. A person wearing these will remain aware of his or her environment, hearing range commands, or other verbal instructions as they were intended.