How Does the Human Body Produce Voice and Speech?
Speech is produced by several parts of the body working together to shape the sounds of the voice.
1. Lungs
Voice is generated by airflow from the lungs.
When the air from the lungs blows through the vocal folds at a high speed, the vocal folds vibrate.
The vibrations lead to sounds we call voice. These sounds are shaped to form speech.
2. Larynx
When it's time to speak, the air pressure below the larynx increases until it blows the vocal folds apart.
3. Vocal Folds
The pressure forces the air through the vocal folds, creating suction as we exhale.
To produce speech, the vocal folds must vibrate normally as air travels through them from the lungs and reaches the mouth and nose.
4. Mouth and Nose
Coordinated movements, mainly by the tongue and lips in the nasal passages, produce recognizable sounds called speech.
More information: https://www.nidcd.nih.gov/voice-speech-video