This is the first of a series of blog entries dealing with what I call a 'phonetic scheme'. It is used to describe phonetic features of spoken English. The scheme is no invention of mine - I do not intend to reinvent the 'phonetic wheel' - but depends heavily on relevant books and articles - too many to be mentioned here. It is intended for teaching purposes and many details of this scheme will be familiar to you.
Here we go then!
Initiation = airstream mechanisms
Inhale, hold you breath, do not exhale and try to say: "Pat-a-cake, pat-a-cake, baker's man. Bake me a cake as fast as you can". Nothing happens. You can't pronounce a single regular speech sound as long as you hold your breath.
Now, inhale again and while you exhale say the two lines of the nursery rhyme again. Well? No problem at all under normal health conditions.
Next, exhale and then inhale and while you inhale try to say the two lines. Did you manage to do it? If not the whole two lines, you were probably able to pronounce at least a fraction of them. What did it feel like? Awkward, dinnit? Our articulatory organs are obviously not used to working properly while we breathe in.
This tiny self-experiment tried to demonstrate that air has to flow either into or (preferably) out of our body if and when we speak. Sound production is initiated by airflow, and this is the reason why this section is called initiation. If we exhale while we speak the airstream is termed egressive (derived from the Latin verb ēgredī, ēgredior, ēgrediēbar, ēgressus sum meaning ' to go out, leave, depart, exit'); otherwise it's an ingressive airstream (from Latin ingredī).
The normal way to recite the nursery rhyme is by exhaling the air out of the lungs - the airstream is pulmonic egressive (the Latin noun for lung is pulmō and the corresponding adjective is pulmōnārius 'of the lung'). If you try to say the rhyme while inhaling air it would be a pulmonic ingressive airstream. You may have heard someone say 'yuh' while inhaling air; another example is French 'oui' said with a pulmonic ingressive airstream.
But the lungs are not the only starting (or end) point of the airstream. Take, for example, the expression "Tsk Tsk!" (or "Tut Tut!"), which is (are) the usual transliteration(s) of the tutting sound made to express disapproval. Try to make this sound and feel the airflow. It's ingressive, i.e. the air is sucked inwards but does not flow into the lungs (you can inhale and exhale while you make the sound). For the air to flow into the oral cavity, the back of the tongue must be sealed against the velum. This is the reason why this kind of airstream mechanism is called velaric.Other velaric ingressive sounds (aka clicks) are the 'kiss sound' (which is a bilabial click), the sound we make when we imitate the clip-clop of hooves (a postalveolar click) or the sound (a lateral click) to make horses speed up.
So far we've mentioned pulmonic egressive and ingressive and velaric ingressive airstream mechanisms. There's another one worth mentioning as a more or less infrequent variant of English sound production: the glottalic egressive airstream. Its use seems to be restricted to the English plosives /k, t, p/. Sound samples can be found here. Sounds articulated with a glottalic egressive airstream are called ejectives.
Airstream mechanisms other than the ones mentioned here are not relevant for English.
The next blog entry in this series will deal with phonation.