Topic-024: The Oro-Nasal Process The possibility of the airstream going out through the mouth, as in v or z, or the nose, as in m and n, is determined by the oro-nasal process. Consider the consonants at the end of rang, ran, ram (ŋ, m, n) which are all nasal sounds. When you say these consonants by themselves, note that the air is coming out through the nose. In the formation of these sounds in a sequence, the point of articulatory closure moves forward, from velar in rang, through alveolar in ran and to bilabial in ram. In each case, air is prevented from going out through the mouth but is able to go out through the nose because the soft palate, or velum, is lowered. In the most speech, soft palate is raised so that there is a velic closure. When it is lowered and there is an obstruction in the mouth, we say that there is a nasal consonant. Raising or lowering the velum controls the oro-nasal process, the distinguishing factor between oral and nasal sounds.
