This section is from the book "The Human Body: An Elementary Text-Book Of Anatomy, Physiology, And Hygiene", by H. Newell Martin. Also available from Amazon: The Human Body.
The Range Of The Human Voice from the lowest note (f of the unaccented octave) of an ordinary bass to the highest note (g on the thrice-accented octave) of a fairly good soprano is about three octaves: the former note is produced by 88 vibrations per second, the latter by 792. Celebrated singers of course go beyond such limit in each direction: bassos have been known to take a on the great octave (55 vibrations per second), and Mozart, at Parma, heard a soprano sing a note of the extraordinarily high pitch c on the fifth accented octave (2112 vibrations per second)
Vowels are musical tones produced in the larynx and modified by resonance of the air in the pharynx and mouth. To get the broad a sounds, as ah, the mouth is widely opened and the lips drawn back; to get such vowels as oo (moor) the lips are protruded and the mouth cavity lengthened. The change in the form of the mouth may be noticed by pronouncing consecutively the vowel-sounds ah, eh, ee, oh, oo. The English i (as in spire) is a diphthong, consisting of a (pad) followed by e (feet), as may be readily found on attempting to sing a sustained note to the sound i.
State the uses of the muscles of the larynx.
What is the ordinary range of the human voice? What notes have celebrated singers taken beyond the ordinary highest and lowest limits?
What are vowels? Illustrate the influence of the shape given to the mouth-cavity in the production of different vowels.