Since the time when people first tried to understand the process of singing, it is used to consider vocal cords as the main source for the singing sound. This is however wrong.
The contemporary singing school teachings are based upon this wrong conception, and the article is meant to present the contradicting discovery, made by a Russian anatomist. It is not yet widely known fact, but the conclusion is that the main source for a proper singing voice is the trachea, and bronchi.
The Russian anatomist Ilya Grusinov in 1812 discovered, that the actual source for a deep and pleasant sound is the membrane, which is a posterior wall of trachea and bronchi. Unfortunately, this discovery did not affect the way singers are taught today, and we only left to wonder how many potential talents get lost.
Ilya Grusinov was anatomizing the dead bodies during and after the war, and first described the audible properties of the membrane. Blowing air through, he found it to produce the sound, very similar to human voice. He describes 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..."
Again, for now the discovery is not widely known, and did not find a generic application in the vocal pedagogic. But instead, the singing teachers are building suppositions and rough assumptions. Still such great singers as Shalyapin and Caruso did understand the theory very well, and used it to gain the success in singing.
In the 1930-ies a different scientist L. Robotnov has set a hypothesis by considering the bronchial system to play the most important role in the vocal formation. He also described techniques on how singers may use breath effectively by minimizing physical efforts and maximizing the resonance. As the author's experience shows, considering the facts above, this is indeed the most effective practical way to teach and study solo singing. The membrane itself has a great capability, provided that it is used efficiently. The great singers could sing as loud as 120-130dB, and we know, that such volume is impossible to gain using vocal cords.
When the author first read about the discoveries, he had an opportunity to visit the dissection-room and carefully examine the tracheae and bronchi of several bodies. Between VI and VII neck bones larynx transforms into trachea, and below, trachea changes into the large bronchial tubes (left and right bronchi). For different body constitutions, the length of tracheae may vary from 3.5 to 6 inch, width varies from 0.5 to 1 inch. Large bronchial tubes are asymmetrically going aside. The length of the right bronchial tube is around 1 to 2 inch, and the left one is 1.5 to 2.5 inch. The membrane serves as the posterior wall of the stack, made of arched cartilage rings. Its width varies from 0.5 to 1 inch.
By itself, the membrane consists of plain elastic longitudinal and transverse muscle fibers. The inner surface of trachea and bronchi is covered by a mucous layer that is vaguely attached to cartilages. In spite of mucous layer being also covered with by various glands, the membrane still has enough degree of freedom to vibrate and form the sound. The large bronchial tubes later are branching into median and minor bronchi.
Such structure provides the "organic" organ tubes and elastic membrane muscle, sufficiently strong to produce bright and resonating sound. It is also necessary to remark that in the lower parts, those attached to the large bronchial tubes, the membrane is much thicker and more solid.
The aim of an educated singer is to learn how to control the vibrations of the membrane intentionally, by adjusting the respiratory system.