Speaking while breathing in?
Play the animation to see the diaphragm expand to produce ingressive airflow.
Although ingressive airflow is possible in the production of speech sounds, no language in the world seems to make distinctive use of this mechanism. There are two good reasons why egressive airflow is the norm in all languages;
- Ingressive airflow does not allow vibration of the vocal folds (phonation). Try saying ‘bee’ and ‘pea’ with ingressive airflow; it’s hard to make them sound different. Click the buttons to hear this. Losing the basis for contrasting series of stops (p and b, t and d, k and g, etc.), is a major limitation.
- Egressive airflow is easy because speakers can use the pressure of full lungs to control slow sustained exhalation. With ingressive airflow, filling the lungs in a slow controlled inhalation is much harder, and it is at odds with the primary function of the lungs which is, of course, to get oxygen into the bloodstream quickly and efficiently.