As humans, we use several mechanisms when speaking, including:

1. Breathing: Controlled inhalation and exhalation of air from the lungs provides the necessary air pressure for speech production.

2. Phonation: Vibration of the vocal cords creates sound, which is modified by the resonating cavities of the mouth, nose, and sinuses.

3. Articulation: Movement of the tongue, lips, jaw, and other speech organs shapes the sound into recognizable speech sounds (phonemes).

4. Prosody: Variations in pitch, rhythm, and stress in speech can convey meaning and add emotional expression to speech.

These mechanisms work together to produce speech, which is a complex and sophisticated form of communication in humans.

The Mechanisms

The oral cavity provides a resonating space for speech sounds to be formed and modified. The shape and size of the oral cavity, along with the position of the tongue, lips, and other speech articulators, determine the sound of speech. The oral cavity helps to produce and modify speech sounds, such as vowels and consonants, by shaping the flow of air and creating a unique resonance for each speech sound. Additionally, the oral cavity helps to amplify speech sounds, making them more audible to listeners. The oral cavity is therefore a key component in speech production and is essential for producing clear, intelligible speech.

The nasal cavity allows for the production of nasal sounds. During speech production, air can escape through the nose if the velum, or soft palate, is lowered. This creates a nasalized sound that is characteristic of certain speech sounds, such as /m/ and /n/. The size and shape of the nasal cavity also play a role in the production of these speech sounds, as they can affect the resonance of the sound produced. Additionally, the nasal cavity can also act as an amplifier for speech sounds, particularly low-frequency sounds, which can help to reinforce speech and make it more audible to listeners. Overall, the nasal cavity plays a significant role in speech production and speech sound quality.

The hard palate, also known as the roof of the mouth, helps articulate speech sounds. The hard palate provides a surface for the tongue to interact with during speech, and its shape and position help to determine the sound of certain speech sounds. For example, the hard palate plays a role in producing sounds like /t/, /d/, /n/, and /l/. The hard palate also helps to separate the oral and nasal cavities, making it possible to produce speech sounds that are not nasalized. Overall, the hard palate plays an important role in shaping the speech sounds produced by the mouth and helps to produce clear and distinct speech sounds.

The velum (soft palate), also known as the soft palate, controls the airflow in the mouth and the nasal cavities. During speech production, the velum raises to separate the oral and nasal cavities, allowing air to escape through the mouth and produce speech sounds. When the velum lowers, air can escape through the nose, creating nasal sounds. The position of the velum is therefore important for producing speech sounds correctly and plays a key role in speech production.

The uvula is a small, muscular flap of tissue located at the back of the mouth, near the velum. While the uvula does not play a direct role in most speech sounds, it does play a role in certain speech behaviours and speech disorders. For example, the uvula can play a role in the production of certain speech sounds in certain languages, such as Arabic or Hebrew.

The pharynx, also known as the throat, plays an important role in speech production. The pharynx is the part of the throat that lies behind the mouth and nose and serves as a passageway for food, liquid, and air. During speech production, the pharynx helps to shape and modify speech sounds by acting as a resonating chamber. The size and shape of the pharynx can affect the resonance of speech sounds, particularly vowel sounds. The pharynx is also involved in the production of certain speech sounds, such as the glottal stop, which is produced by briefly closing the space at the back of the pharynx. Additionally, the pharynx plays a role in swallowing and breathing, making it important for speech and overall health. Overall, the pharynx plays an important role in speech production and speech sound quality.

The glottis is the space between the vocal cords in the larynx (voice box). The glottis controls the flow of air from the lungs to the pharynx and oral cavity. During speech production, the glottis can either be open or closed, allowing or blocking the flow of air, respectively. When the glottis is open, air from the lungs flows freely and produces voiced speech sounds, such as vowels. When the glottis is closed, the flow of air is blocked, creating unvoiced speech sounds, such as /s/ or /f/. The glottis also plays a role in producing the sounds of the glottal stop, which is produced by briefly closing the space at the back of the pharynx. The glottis is therefore a key component of speech production and plays an important role in shaping speech sounds and producing clear, intelligible speech.

The larynx, also known as the voice box, plays a crucial role in speech production. The larynx contains the vocal cords, which are two folds of mucous membrane that vibrate when air from the lungs is expelled through them. This vibration produces sound, which is shaped and modified by the surrounding structures to produce speech sounds. The larynx also has a cartilaginous structure known as the thyroid cartilage that acts as a "soundboard" for speech sounds, helping to reinforce and shape the speech sounds produced by the vocal cords. The larynx also plays a role in breathing, as it can either open to allow air to flow freely into the lungs or close to protect the airway during swallowing. Additionally, the position of the larynx can affect the resonance of speech sounds, particularly vowels. Overall, the larynx plays a crucial role in speech production, serving as the source of sound for speech and helping to shape and modify speech sounds.