A trill consonant is a consonant that is made by vibrating an articulator, or hitting it many times against something else. For example, the <rr> in the Spanish word "perro" is an alveolar trill, where the tongue is hit many times against the alveolar ridge, or the place just behind the teeth. This vibration is caused by a flow of air.
There are three trill consonants in the International Phonetic Alphabet. These are:
- [r] - alveolar trill
- [ʙ] - bilabial trill, where the lips are trilled.
- [ʀ] - uvular trill, where the uvula is trilled.