The production of speech
To describe how we produce speech and what speech looks like acoustically in the space of a single chapter is a tall order, and you would do well to consult other textbooks that deal more specifically with the phonetics of speech, like Ladefoged (2006), Catford (1988), Laver (1994), Ladefoged & Maddieson (1996) or Reetz & Jongman (2009). We describe the speech production process in two stages. First, we consider the role of the lungs and the larynx. This part of the speech organs is responsible for the actions of the vocal folds, which are located inside the larynx. A common and spectacular action of the vocal folds occurs when they vibrate against each other so as to produce a buzzing sound, which can be varied in pitch and loudness. Second, we deal with the role of the channel extending from the larynx onwards, called the vocal tract. It is formed by the pharynx, the mouth and, for nasal and nasalized sounds, the nasal cavity. The vocal tract modifies the buzzing larynx sound-which we cannot reproduce here in its pristine form, unless the vocal folds are made to vibrate artificially in a headless cadaver. Because the vocal tract can assume many different shapes, these modifications are highly varied. The most striking effect here is the production of different vowel sounds. The term organs of speech is used to refer to parts of the body in the larynx and the vocal tract that are involved in the production of speech. It is a misleading term in that it suggests that we have special physical organs for speaking. This is not so: all our so-called ‘organs of speech’ have primary biological functions relating to our respiratory system and the processing of food.