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The human voice consists of sound Voice production by a human being using the vocal tract, including Speech, singing, Laughter, crying, screaming, shouting, humming or yelling. The human voice frequency 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 Voicelessness, Click consonant, 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, Soft palate, cheek, , etc.) articulate and Band-pass 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 vocal folds, in combination with the speech organ, are capable of producing highly intricate arrays of sound.Stevens, K.N.(2000), Acoustic Phonetics, MIT Press, , 978-0-262-69250-2 Titze, I.R. (1994). Principles of Voice Production, Prentice Hall (currently published by NCVS.org), .Titze, I. R. (2006). The Myoelatic Aerodynamic Theory of Phonation, Iowa City:National Center for Voice and Speech, 2006. The tone of voice may be modulated to suggest such as anger, surprise, fear, happiness or sadness. The human voice is used to express emotion, and can also reveal the age and sex of the speaker. use the human voice as an instrument for creating music.
The folds are within the larynx. They are attached at the back (side nearest the spinal cord) to the arytenoids cartilages, and at the front (side under the chin) to the thyroid cartilage. They have no outer edge as they blend into the side of the breathing tube (the illustration is out of date and does not show this well) while their inner edges or "margins" are free to vibrate (the hole). They have a three layer construction of an epithelium, vocal ligament, then muscle (vocalis muscle), which can shorten and bulge the folds. They are flat triangular bands and are pearly white in color. Above both sides of the vocal cord is the vestibular fold or false vocal cord, which has a small between its two folds.
The difference in vocal fold size between men and women means that they have differently pitched voices. There is also genetics variation amongst the same sex, with men's and women's singing voices being categorized into types. For example, among men, there are bass, bass-baritone, baritone, baritenor, tenor and countertenor (ranging from E to E and higher), and among women, contralto, alto, mezzo-soprano and soprano (ranging from F to C and higher). There are additional categories for operatic voices, see voice type. This is not the only source of difference between male and female voice. Men, generally speaking, have a larger vocal tract, which essentially gives the resultant voice a lower-sounding timbre. This is mostly independent of the vocal folds themselves.
The ability to vary the ab/adduction of the vocal folds quickly has a strong genetic component, since vocal fold adduction has a life-preserving function in keeping food from passing into the lungs, in addition to the covering action of the epiglottis. Consequently, the muscles that control this action are among the fastest in the body. Children can learn to use this action consistently during speech at an early age, as they learn to speak the difference between utterances such as "apa" (having an abductory–adductory gesture for the p) as "aba" (having no abductory–adductory gesture). They can learn to do this well before the age of two by listening only to the voices of adults around them who have voices much different from their own, and even though the laryngeal movements causing these phonetic differentiations are deep in the throat and not visible to them.
If an abductory movement or adductory movement is strong enough, the vibrations of the vocal folds will stop (or not start). If the gesture is abductory and is part of a speech sound, the sound will be called voiceless. However, voiceless speech sounds are sometimes better identified as containing an abductory gesture, even if the gesture was not strong enough to stop the vocal folds from vibrating. 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).
An adductory gesture is also identified by the change in voice spectral energy it produces. Thus, a speech sound having an adductory gesture may be referred to as a "glottal stop" even if the vocal fold vibrations do not entirely stop.
Other aspects of the voice, such as variations in the regularity of vibration, are also used for communication, and are important for the trained voice user to master, but are more rarely used in the formal phonetic code of a spoken language.
Singers can also learn to project sound in certain ways so that it resonates better within their vocal tract. This is known as vocal resonation. Another major influence on vocal sound and production is the function of the larynx, which people can manipulate in different ways to produce different sounds. These different kinds of laryngeal function are described as different kinds of vocal registers. The primary method for singers to accomplish this is through the use of the singer's formant, which has been shown to be a resonance added to the normal resonances of the vocal tract above the frequency range of most instruments and so enables the singer's voice to carry better over musical accompaniment.Sundberg, Johan, The Acoustics of the Singing Voice, Scientific American Mar 77, p82 E. J. Hunter, J. G. Svec, and I. R. Titze. Comparison of the Produced and Perceived Voice Range Profiles in Untrained and Trained Classical Singers. J. Voice 2005.
In linguistics, a register language is a language that combines tone and vowel phonation into a single phonology system.
Within speech pathology, the term vocal register has three constituent elements: a certain vibratory pattern of the vocal folds, a certain series of pitches, and a certain type of sound. Speech pathologists identify four vocal registers based on the physiology of laryngeal function: the vocal fry register, the modal register, the falsetto register, and the whistle register. This view is also adopted by many vocal pedagogists.
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