Vocal folds in the context of "Voice"

The human voice consists of sound made by a human being using the vocal tract, including talking, singing, laughing, crying, screaming, shouting, humming or yelling. The human voice is specifically a part of human sound production in which the vocal folds (vocal cords) are the primary sound source. (Other sound production mechanisms produced from the same general area of the body involve the production of unvoiced consonants, clicks, whistling and whispering.)

Generally speaking, the mechanism for generating the human voice can be subdivided into three parts; the lungs, the vocal folds within the larynx (voice box), and the articulators. The lungs, the "pump" must produce adequate airflow and air pressure to vibrate vocal folds. The vocal folds (vocal cords) then vibrate to use airflow from the lungs to create audible pulses that form the laryngeal sound source. The muscles of the larynx adjust the length and tension of the vocal folds to 'fine-tune' pitch and tone. The articulators (the parts of the vocal tract above the larynx consisting of tongue, palate, cheek, lips, etc.) articulate and filter the sound emanating from the larynx and to some degree can interact with the laryngeal airflow to strengthen or weaken it as a sound source.

The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology and speech production in general. Phoneticians in other subfields, such as linguistic phonetics, call this process voicing, and use the term phonation to refer to any oscillatory state of any part of the larynx that modifies the airstream, of which voicing is just one example. Voiceless and supra-glottal phonations are included under this definition.

Voice projection is the strength of speaking or singing whereby the human voice is used powerfully and clearly. It is a technique employed to command respect and attention, such as when a teacher talks to a class, or simply to be heard clearly, as used by an actor in a theatre or during drills.

Breath technique is essential for proper voice projection. In normal talking, one may use air from the top of the lungs. A properly projected voice uses air flowing from the expansion of the diaphragm. In good vocal technique, well-balanced respiration is especially important to maintaining vocal projection. The goal is to isolate and relax the muscles controlling the vocal folds, so that they are unimpaired by tension. The external intercostal muscles are used only to enlarge the chest cavity, whilst the counterplay between the diaphragm and abdominal muscles is trained to control airflow.

A tremor is an involuntary, somewhat rhythmic muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the hands. In some people, a tremor is a symptom of another neurological disorder.

Modal voice is the vocal register used most frequently in speech and singing in most languages. It is also the term used in linguistics for the most common phonation of vowels. The term "modal" refers to the resonant mode of vocal folds; that is, the optimal combination of airflow and glottal tension that yields maximum vibration.

In linguistics, modal voice is the only phonation found in the vowels and other sonorants (consonants such as m, n, l, and r) of most of the languages of the world, but a significant minority contrasts modal voice with other phonations. Among obstruents (consonants such as k, g, t͡ʃ/ch, d͡ʒ/j, s, and z), it is very common for languages to contrast modal voice with voicelessness, but in English, many supposedly-voiced obstruents do not usually have modal voice.

An oral consonant is a consonant sound in speech that is made by allowing air to escape from the mouth, as opposed to the nose, as in a nasal consonant. To create an intended oral consonant sound, the entire mouth plays a role in modifying the air's passageway. This rapid modification of the air passageway using the tongue and lips makes changes to the waveform of the sound by compressing and expanding the air. In addition to the nose and mouth, the vocal cords and lungs also make a contribution to producing speech by controlling the volume (amplitude) and pitch (frequency) of the sound. The use of the vocal cords will also determine whether the consonant is voiced or voiceless. Most consonants are oral, such as, for example [p], [w], [v] and [x]. The others are nasal, such as the nasal occlusives [m] or [n].

In linguistics, creaky voice (sometimes called laryngealisation, pulse phonation, vocal fry, or glottal fry) refers to a low, scratchy sound that occupies the vocal range below the common vocal register. It is a special kind of phonation in which the arytenoid cartilages in the larynx are drawn together; as a result, the vocal folds are compressed rather tightly, becoming relatively slack and compact. They normally vibrate irregularly at 20–50 pulses per second, about two octaves below the frequency of modal voicing, and the airflow through the glottis is very slow. Although creaky voice may occur with very low pitch, as at the end of a long intonation unit, it can also occur with a higher pitch. All contribute to make a speaker's voice sound creaky or raspy.

The glottis (pl.: glottises or glottides) is the middle region of the larynx, where the vocal folds are located. Within this region is the opening between the vocal folds (the rima glottidis). The glottis is crucial in producing sound from the vocal folds.