Speech distinguishes humans from other apes. The physical aspect of speech pertains to the vocal chords, the larynx, the positioning of the tongue and the lips. Each of these plays a vital role in helping humans to speak. Of course, the brain coordinates the movement for speech functions as well as other functions.
The vocal chords
The essential human speech or sounds are made when air is passed over the two vibrating elements known as the vocal chords. When the right amount of tension is applied on the vocal chords, the tone of the speech can become higher or lower. Modulation of the speech is done by the larynx. In this, the mouth and the nose chambers that are present help the larynx is modulating the speech. The Vocal cords are present inside the throat and can be used for producing various types of sounds.
Vocal cords, also known as vocal folds, are made up of twin introversions of mucous membrane and these remain stretched horizontally across the larynx. Vocal cords vibrate and modulate the flow of air. When we talk, the will also stiffen and also move closer to each other. Finally, the sounds and the words are produced when the tongue is moved in a particular direction along with the positing of the lips. The volume of the sounds is essentially controlled by increasing or decreasing the amounts of air that would pass through the vocal chords.
It is also known as voice box, positioned among pharynx and trachea and is a 2-inch-long, tube-shaped organ in the neck. Larynx is extensively used for talking and even breathing. It is also essential for swallowing. The external wall of cartilage of larynx is responsible for the shape of the “Adams apple.”
Brain is the centre that controls speech and hearing as well. In fact, both are even interconnected. It controls the phonetic sounds and the articulation of the sounds.
Human speech also undergoes changes when a human reaches puberty. This is especially pronounced for boys. Since the vocal chords become thicker and the resonance chamber also increases, the voice modulation and quality changes. This is the reason, that pubescent boys sound different and their voice sounds hoarse or heavy. At times that voice will also sound squeaky and funny. This is because, at this time, they are also learning to modulate their vocal chords again.
The organs that are involved in the speech process for humans
Our lips, teeth, tongue and the mouth are used in various positions to emanate the sounds that we want to make. The uvula located inside our mouth is used specifically when we want to make some guttural noises. The uvula is also useful for making speaking the nasal tones by stopping the air from going inside the noise.
The vibrations that emanate from the vocal chords are controlled by the glottis and this helps us to make various sounds as well. The tongue taps and even touches the alveolar ridge and the hard palate inside our mouth when we are speaking and making different noises in that process.