The vocal tract

Speech as coordinated movement

Most speech sounds begin with air pushed from the lungs. It passes through the larynx, then through the throat and mouth; lowering the velum also opens a route through the nose. The vocal folds may vibrate, remain apart, or briefly close. The tongue, lips and jaw reshape the passage. A consonant places a substantial constriction somewhere along it. A vowel normally leaves the oral passage relatively open while the tongue and lips shape resonances. The diagram is a schematic side view, not an anatomical scan: select a labelled structure to see its role.

Phonetics studies production, transmission and perception. Articulatory phonetics asks what the organs do; acoustic phonetics asks what changes in the sound wave; auditory phonetics asks how listeners hear it. Phonology asks how a particular language organizes these possibilities into meaningful contrasts and patterns. An IPA symbol is a precise convention for a sound category, not a letter of every language's alphabet.

Place of articulation

Place names the region where an active articulator approaches a passive one. In [p], the lower and upper lips meet: bilabial. In [f], the lower lip approaches the upper teeth: labiodental. Dental [θ] uses the tongue and teeth; alveolar [s] uses the ridge just behind them. Postalveolar [ʃ] is slightly farther back. Retroflex [ʈ] involves the tongue tip curled or drawn back toward the postalveolar region; its exact realization varies. Palatal [c] uses the tongue body near the hard palate; velar [k] uses its back at the soft palate; uvular [q] is farther back. Pharyngeal [ħ] narrows the throat; glottal [ʔ] closes at the vocal folds.

A place label is a useful abstraction, not a promise that every speaker makes an identical gesture. Coarticulation means neighboring segments overlap in time, so a consonant can acquire secondary rounding, palatalization or nasalization. A chart locates a primary constriction while diacritics record further detail.

Manner of articulation

Manner describes what happens to airflow at the constriction. A plosive (oral stop) completely blocks oral and nasal airflow before release; [p] and [b] differ principally in voicing. A nasal also blocks the mouth but lowers the velum, allowing air to escape through the nose, as in [m]. A fricative narrows the passage enough for turbulent noise, as in [s]. An approximant narrows it without that strong turbulence, as in [j]. A lateral lets air escape along the sides of the tongue, as in [l]. A trill repeatedly vibrates an articulator; a tap or flap makes one brief contact. An affricate begins as a stop and releases into frication, conventionally written with a tie bar when needed: [t͡ʃ].

Voicing is another dimension. Touch your throat and alternate a sustained [s] with [z]: vibration is usually felt during [z]. Do not treat voiceless as a synonym for whispering; whisper is a broader voice quality. Aspiration, such as [pʰ], is a delay before voicing begins after a stop's release. Some languages contrast that delay, while others distribute aspirated and unaspirated variants by context.

Airstream mechanisms

Pulmonic egressive speech pushes lung air outward; the large consonant table uses this mechanism. Clicks create a rarefaction between two oral closures and release the front closure. Implosives involve a glottalic ingressive gesture. Ejectives compress air between a closed glottis and an oral closure, then release it. The IPA groups these separately because place and manner alone do not specify the airstream. WALS documents clicks, labial-velars, pharyngeals and dental fricatives across its comparative sample; “uncommon” in a sample does not mean difficult, primitive or marginal.