The correct transmission of the sound demands that every register be well-defined, well-placed—every register having its special mechanism. 

According to García, the voice's of women have three registers: 1) the chest register, 2) the medium or fausett, 3) the head register. García joins these last two into one: the fausset-téte. In fact, experience shows us that this register (f to b) must be supported in the head—and therein lies the difficulty. Today, we constantly see the medium (especially the students of men) being sung in chest voice. This brings about difficulty that tests the professor, one that is not very experienced or skillful, to explain the manner in which to make the sounds and establish the passage from chest to medium. In this case, students are heard to sing chest in fausset (which is often the case in France), and the medium in chest voice, on the vowel well-opened, which forms open and white voices, which one hears a lot now-a-days, and which García characterized as a the sound of a duck. 

This passage between chest and the medium, which is so difficult to establish, sometimes disgusts the student, but it should be noted that even the student endowed with ordinary capacities will understand it easily enough; while, for the others, one has to resort to a vocal demonstration with one's own voice. But what can a male professor do, who's voice in this range is feminine and not at all the one in which he sings? 

The open sound, of which I have just spoken is, unfortunately, a general thing in the teaching of all countries. And I must note that, except in some rare exceptions, almost all these students have a very open sound which comes from singing the medium register in chest.

The main difficulty is explaining the passage from chest to medium, which demands a true gift and special intuition on the part of a professor. When we hear a pupil singing with a very open sound, it means that the medium range is being sung in chest voice. This is the first rule of Garcia's teaching, which is fundamental, since the future and health of the voice—as well as correct emission— depend on this poise.   

—A student of Pauline Viardot-García c. 1900