Complex sentence: Ilya Gruzinov was professor of anatomy and physiology at Imperial Moscow University who 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.
Split into simpler sentences: Ilya Gruzinov was professor of anatomy and physiology at Imperial Moscow University. 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.