Process of speech

The vocal cords - elastic ligaments covered by mucous membrane.

They are stretched between rigid pieces of cartilage in the larynx

Vibration produces sound

Tightness of the vocal cords may be altered by muscles attached to the vocal cords

More contracted these muscles ---- tighter the cords ---- gap between the cords more narrow ---- higher pitched note

Diaphragm and intercostal muscles control rate of flow of air through the cords ---- greater the pressure ---- louder the noise.

Resonation through the pharynx and nasal cavity

Speech further modified by the action of the tongue, lips and facial muscles

Men - thicker vocal cords than women so have deeper voices - occurs at puberty and is responsible for the voice `breaking`

Controlled by recurrent laryngeal nerves which branch off the vagus nerve