Q for the techies
Whilst I understand the basic principle of ANR and have read bits and pieces about it on the web, one question has always remained with me..
Does the introduction of the noise-cancelling sound wave, whilst cancelling out what you hear, actually increase the force of sound (energy), albeit inaudible, hitting your eardrums?
"Active cancellation involves the "addition" of sound waves...one wave mixing with another.."
"While it might seem odd to add large amounts of "new" sound energy into the dome cavity and ear canal, that's exactly how these active systems work. A microphone picks up the frequency and amplitude profile at an instant in time inside the dome cavity, the signal is processed and amplified by the electronics.."
After recently purchasing an ANR set, I was intrigued to find that whilst it was obviously noticeably quieter during flight with the unit switched on, after a decent-length duty airborne I felt like my eyeballs were being forced out of their sockets!
Inaudible sound energy??