To create speech, around a hundred different muscles in the chest, neck, jaw, tongue, and lips must work together. Every word or short phrase that is physically spoken is followed by its own unique arrangement of muscle movements. The information necessary for producing a phrase is saved in the speech area of the brain.
The tone present in the voice of the speaker shows many different possible things, one of such example being the current emotional state, and is changed in regards to the rapidity of the muscle movement. Humans can output around fourteen sounds per second, while particular components of the speech process, such as those in the tongue, lips, and jaw cannot create more than two actions per second.
The facial muscles play possibly the most important role in the articulation of speech and the transmission of emotions through it. The frontalis muscle is in the forehead and is only used for facial expressions in humans. Its main function is to lift the eyebrows, particularly when looking upwards, and is joined for some length above the root of the nose. It helps with emotional expression in speech.
The orbicularis oris muscle is a composite of muscles in the lips and surrounds the mouth. It is made up of four separate quadrants that interconnect. This muscle allows the mouth to be closed, and puckers the lips when contracted, which allows for the act of kissing.
The buccinator muscle forms the anterior part of the cheek and pulls the angle of the mouth back while straightening the cheeks. This constricts them against the teeth, which allows for significantly more expression and sound articulation.