When recently listening to a radio broadcast with poor sound quality, I was struck by how much more intelligible the female reporters’ voices were than those of the males (whose low tones so muddied their words that they became a mumble).
In science class, we learned that speaking with a larynx full of helium caused our voices to rise in pitch.
Today’s invention is for male aircrew who wear oxygen masks and need to communicate very clearly.
It consists of a small cylinder of Helium or other low density gas, a tiny squirt of which is injected into the mask when its wearer begins to speak.
This raises the pitch of the speech which is transmitted, making it less garbled.