Here some EHA information notice => the best practices applied by our members in the various EU Countries.
http://www.eha-heli.eu/images/News/I...NAL_090420.pdf
Regarding the mic and mask, some solution here ->
https://www.heliopsmag.com/tiger-per...r-aviation-use
Also => look for some existing throat mic solutions from Kenwood, Motorola and similar, with price level 30 USD and up,
your local avionic shop can easy adapt one.