QUIETPRO+ was designed for and is in use by several nations’ armed forces, including the U.S. Army. Now, the makers of the device have announced that they are starting work on the next generation of hearing protection for offshore oil rig workers. Besides blocking and transmitting sound, each earplug also contains two microphones, one that sits inside the ear canal and one located externally. The internal mikes pick up and wirelessly transmit the user’s voice, while the external ones detect sounds in the surrounding environment. When there is little noise, the system allows the user to electronically hear their environment as it is, or to even turn up the gain and hear it better. As the environment gets louder, the system will first lower the playback volume of the offending noise, then will proceed to introduce its own inverse sound waves that cancel out the loud external ones. Because the user’s voice mikes are located inside their ear canal, which is already protected, they can transmit their voice without any accompanying external noises. Although a voice picked up inside someone’s ear might initially sound rather muffled, a digital signal processor sharpens it up before it hits the airwaves. This means that two users could easily have a conversation with one another, even if surrounded by loud engine noise or gunfire.

(Source: Gizmag)