What distinguishes consonants from vowels?

The distinguishing feature between consonants and vowels is that consonants involve a significant degree of constriction or blockage at some point in the vocal tract, while vowels are produced with a relatively open vocal tract. This constriction can occur at various locations, such as the lips, teeth, or throat. When producing consonants, airflow is partly restricted, which creates different sounds depending on the place and manner of articulation.

In contrast, vowels are characterized by an open configuration of the vocal tract, allowing air to flow freely without obstruction. This open state is what enables vowels to carry the most sonority in speech and typically allows for more variation in pitch and quality compared to consonants. This fundamental difference in airflow and articulation is key to understanding the phonetic distinctions between these two categories of speech sounds.