It's called apnoea and it's because a baby's breathing mechanism
isn't mature at birth so very fast breaths follow a period without a breath.
The text ends with four appendices: Appendix I--International Phonetic Alphabet, with consonant formation guidelines; Appendix II--Hands on the back of the chair: A "position of mechanical advantage" for re-educating the breathing mechanism
; Appendix III--Contact Information; and Appendix I--Notation, pitch names and frequency correlation chart.
For example, chapter 4, "Breath Energy in Singing," offers a clearly written, highly detailed description of the workings of the breathing mechanism
along with high quality anatomical drawings that will be helpful to any singer.
What is particularly challenging about Verdi's vocal writing is the demands he makes on the breathing mechanism
. All singing obviously begins with the breath.