Human voice

The articulators (the parts of the vocal tract above the larynx consisting of tongue, palate, cheek, lips, etc.)

The vocal folds, in combination with the articulators, are capable of producing highly intricate arrays of sound.

[2][3][4] The tone of voice may be modulated to suggest emotions such as anger, surprise, fear, happiness or sadness.

Men, generally speaking, have a larger vocal tract, which essentially gives the resultant voice a lower-sounding timbre.

Human spoken language makes use of the ability of almost all people in a given society to dynamically modulate certain parameters of the laryngeal voice source in a consistent manner.

This anomalous feature of voiceless speech sounds is better understood if it is realized that it is the change in the spectral qualities of the voice as abduction proceeds that is the primary acoustic attribute that the listener attends to when identifying a voiceless speech sound, and not simply the presence or absence of voice (periodic energy).

The sound of each individual's voice is thought to be entirely unique[13] not only because of the actual shape and size of an individual's vocal cords but also due to the size and shape of the rest of that person's body, especially the vocal tract, and the manner in which the speech sounds are habitually formed and articulated.

Humans have vocal folds that can loosen, tighten, or change their thickness, and over which breath can be transferred at varying pressures.

A register in the human voice is a particular series of tones, produced in the same vibratory pattern of the vocal folds, and possessing the same quality.

[20] Vocal resonation is the process by which the basic product of phonation is enhanced in timbre and/or intensity by the air-filled cavities through which it passes on its way to the outside air.

Various terms related to the resonation process include amplification, enrichment, enlargement, improvement, intensification, and prolongation; although in strictly scientific usage acoustic authorities would question most of them.

The main point to be drawn from these terms by a singer or speaker is that the result of resonation is, or should be, to make a better sound.

Analysis of recorded speech samples found peaks in acoustic energy that mirrored the distances between notes in the twelve-tone scale.

[22] There are many disorders that affect the human voice; these include speech impediments, and growths and lesions on the vocal folds.

Talking improperly for long periods of time causes vocal loading, which is stress inflicted on the speech organs.

Speech-language therapy teaches the patient how to eliminate the irritations permanently through habit changes and vocal hygiene.

Hoarseness or breathiness that lasts for more than two weeks is a common symptom of an underlying voice disorder such as nodes or polyps and should be investigated medically.