He discovered in 1812 that the actual source for a deep and pleasant vocal sound is the membrane, which is a posterior wall of trachea and bronchi.
Gruzinov was born to a family of an ethnic Georgian priest of Russian orthodox Church.
[1] After Napoleon's invasion of Russia in 1812 he began to help wounded soldiers in the Russian Army.
Gruzinov made his discovery while dissecting dead bodies during and after the Battle of Borodino, and first described the audible properties of the membrane.
He described this best himself: "Anatomizing the dead bodies, by inflating the windpipe and stretching the membranous posterior wall of trachea, I have managed to produce a perfect vocal sound without engaging the vocal cords..." "Human voice is formed in the chest - in the bottom end of the windpipe (trachea), by means of the posterior membrane, attached to the cartilaginous cells..." Gruzinov died from typhus in January 1813.