Which term would you use to classify the consonant sounds /b/, /m/, /p/, and /w/?

• A. Bilabial
• B. Labiodental
• C. Velar
• D. Glottal

Answer: (A)

Consonant place of articulation: bilabial means the constriction is formed with the lips. The sounds /b/ and /p/ are classic bilabial plosives, with a complete closure at the lips and voice onset differing between them. /m/ is a bilabial nasal, produced with the lips closed so air goes through the nose. /w/ is described as a bilabial approximant in terms of where the constriction occurs—the lips come together to shape the sound, even though the tongue and the velum may also participate. The other options involve different locations: labiodental uses the lower lip against the upper teeth, velar uses the back of the tongue against the soft palate, and glottal involves the vocal cords. So, the classification that fits all four sounds is bilabial.