kwizza ...thanks...what caught my eye is from your links (last sentence):
"INVISIO Digital is the next generation bone conductive microphone headset from Nextlink.to A/S. It has several new features such as a DSP (Digital Signal Processing). The DSP technology manipulates the analog audio signals and turns them into digital signals thus improving the audio quality dramatically. Furthermore the INVISIO Digital has an external "spy-mike" that can enhance the hearing of the user with 8 - 10 times. The "spy-mike" can also be disabled and the built-in limiter function cuts any sudden high noise or explosions from reaching your ear".
Bit by bit by bit noise protection is being eked into new products "on the sly" which is good news for us as it suggest to me that firms see this as a valuable functional requirement to get into the product?