Resonators.

The resonators are cavities where there airstream that is coming from the lungs is blocked completely or partially by the active articulators giving them to the airstream special qualities in the release, these are acoustic qualities.
The resonators can be: nasal cavity, oral cavity, pharyngeal cavity. In red is indicated the nasal cavity, which helps in the production of nasal sounds. In green colour is indecated the oral cavity, which is very important because the most part of the sounds are produced in this area and finaly the pharyngeal cavitywhere the sound that comes from the lungs is afected by this. Increasing its sound.