How Consonants Shape the Air on Its Way Out
Speech begins with air pushed up from the lungs. As it passes through the voice box and vocal tract, the lips, tongue, teeth, and soft palate shape its route. A consonant is made by narrowing that route, briefly closing it, or directing air through a different passage. These movements give consonants their characteristic sounds.
Try three different gestures. For “t,” the tongue briefly seals off airflow in the mouth, then releases it. For “f,” the lower lip approaches the upper teeth, squeezing air through a narrow gap. For “m,” the lips close the oral passage, but the soft palate lowers so air can escape through the nose. The sound is not simply air stopping; its path changes.
Why Those Small Changes Make Speech Clear
The vocal folds can vibrate as air moves through them, adding voice, or remain apart, producing a whisper-like sound. That voicing can vary while the mouth makes a similar consonant gesture: compare the voiced “v” with the unvoiced “f.” Listeners use both the airflow-shaped sound and the timing of its release to tell them apart.
Vowels generally leave the vocal tract more open, allowing sound to resonate through the mouth. Consonants create sharper transitions by shaping or redirecting the airflow. In a spoken word, those transitions help signal where one sound ends and the next begins—often with a movement too quick to notice consciously, but precise enough to make “fan” sound different from “van.”
