The voiced bilabial nasal is a consonant made by closing both lips while air escapes through the nose. Because the vocal folds vibrate during the sound, it is voiced; because the closure is at the lips, it is bilabial; and because the oral passage is blocked while the soft palate is lowered, it is nasal.

How it is produced

In phonetic terms, [m] is a nasal sonorant produced with pulmonic egressive airflow. Speakers hold the lips together, lower the velum, and let resonance pass through the nasal cavity. The result is the familiar humming quality heard at the start of words such as map and in the middle or end of rum.

Occurrence in languages

This sound is very common around the world and appears in spoken languages across many language families. It is often part of a basic consonant inventory because it is easy to articulate and combines well with surrounding vowels and vowels-like sonorants. A few languages either lack it or use it only in restricted ways; Mohawk is sometimes cited as an example of a language where it is not especially prominent.

  • Place of articulation: bilabial, with both lips involved.
  • Manner of articulation: nasal, with airflow through the nose.
  • Voicing: voiced, with vibration of the vocal folds.
  • Common contrast: it differs from the oral stop b and from other nasal consonants such as alveolar or velar nasals.

Writing and symbols

In the International Phonetic Alphabet, this sound is written ⟨m⟩. The same symbol is also used in X-SAMPA, where it is transcribed as m. In many alphabetic writing systems, the letter m commonly represents this consonant, although spelling conventions vary from language to language.

English

English uses the voiced bilabial nasal in ordinary words such as map, time, and rum. It normally occurs at the beginning, middle, and end of syllables, and it contrasts with the voiced bilabial stop b and with other nasal sounds in English phonology.

Because it is widespread, stable, and easy to recognize, [m] is one of the most familiar consonants in spoken language. It also serves as a useful reference sound in phonetics, speech teaching, and language description, where it helps illustrate how place of articulation, voicing, and nasal airflow combine to form a single consonant.