A nasal consonant is a type of speech sound produced when air flows through the nose while the mouth is closed. This occurs when the soft palate lowers, allowing the sound to resonate in the nasal cavity. Common examples of nasal consonants include the sounds represented by the letters m, n, and ŋ (as in "sing"). Nasal consonants are important in many languages, contributing to the distinctiveness of words. They can change the meaning of words when substituted for other consonants. For instance, the words man and pan differ only in their initial consonants, showcasing the role of nasal sounds in language.