What are nasal sounds?

There are three nasal sounds in American English pronunciation: the 'm sound' /m/, 'n sound' /n/, and 'ng sound' /ŋ/.

The two major points that beginner ESL/ELL students should understand about nasal sounds are: 

1. The air is completely blocked from leaving the mouth, and is instead released out through the nose.
2. All three nasal sounds are voiced, meaning that the vocal cords vibrate during the creation of the sound.

A subtle aspect of /n/ to be aware of is:

1. The /n/ can become 'syllabic' on unstressed syllables.

The /n/ as a syllabic consonant

A syllabic consonant is a consonant sound that becomes the base sound of a syllable (meaning that there is no vowel sound included in the syllable). On an unstressed syllable, the /n/ can become syllabic. For instance, there is no vowel sound in the second syllable of the words 'sudden' or 'golden.'

sudden /'sʌd n/

burden /'bɚ n/