What sound is produced when both lips come together during articulation?

The sound produced when both lips come together during articulation is categorized as a bilabial sound. Bilabial sounds are formed by blocking the airflow with both lips and then releasing it, which allows for the distinct sound to be produced. Common examples of bilabial sounds in English include /p/, /b/, and /m/.

This term originates from the prefixes "bi-" meaning two and "labial," which refers to the lips. When both lips touch, they create a closure that is crucial for these sounds. Understanding this concept is fundamental for studying phonetics as it highlights how different parts of the mouth contribute to sound production.

Other choices represent different articulatory processes. Fricative sounds involve the air flowing through a narrow channel made by placing two articulators close together, resulting in turbulence. Nasal sounds are produced when air flows through the nose as well as the mouth due to a lowered velum. Labiodental sounds are articulated by placing the lower lip against the upper teeth, which is distinct from the bilabial mechanism of using both lips.