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Voice types and the anatomy of the vocal cords.

The human voice consists of sound made by the vocal folds or 'cords' for talking, singing, laughing, crying and screaming. The vocal folds, in combination with the lips, the tongue, the lower jaw, and the palate, are capable of producing highly intricate arrays of sound. The tone of voice may be modulated to suggest emotions such as anger, surprise, or happiness.

Men and women have different vocal cord sizes; adult male voices are usually lower-pitched and have larger cords. The male vocal cords (which would be measured vertically in the opposite diagram), are between 17 mm and 25 mm in length. Female vocal cords are between 12.5 mm and 17.5 mm in length.As seen in the illustration, the cords are located just above the trachea (the windpipe which travels from the lungs).

Food and drink does not pass through the cords but is instead taken through the eosophagus , a separate tube. Both tubes are separated by the tongue and an automatic gag reflex. When food goes down through the cords and trachea it causes choking.Cords are ligaments within the larynx. They are attached at the back (side nearest the spinal cord) to the arytenoid cartilages, and at the front (side under the chin) to the thyroid cartilage. Their outer edges, as shown in the illustration above, are attached to muscle in the larynx while their inner edges or "margins" are free (the hole).

They are constructed from epithelium, but they have a few muscle fibres on them, namely the vocalis muscle which tightens the front part of the ligament near to the thyroid cartilage. They are flat triangular bands and are pearly white in colour—whiter in females than they are in males.

The difference in vocal cord size between men and women means that they have differently pitched voices. Additionally, genetics also causes variances amongst the same sex, with men and women's voices being categorised into types. For example, among men, there are basses, baritones and tenors, and altos, mezzo-sopranos and sopranos among women. There are different methods for categorizing voices, such as the fach in German opera, and vocal weight in British opera.

The human voice is capable in most cases of being a complex instrument. Humans have vocal folds which can loosen or tighten or change their thickness and over which breath can be transferred at varying pressures. The shape of chest and neck, the position of the tongue, and the tightness of otherwise unrelated muscles can be altered. Any one of these actions results in a change in pitch, volume, timbre, or tone of the sound produced. One important categorization that can be applied to the sounds singers make relates to the register or the "voice" that is used. Singers refer to these registers according to the part of the body in which the sound most generally resonates, and which have correspondingly different tonal qualities. There are widely differing opinions and theories about what a register is, how they are produced and how many there are. The distinct change or break between registers is called a passaggio or a ponticello. The following definitions refer to the different ranges of the voice.

The chest voice is the register typically used in everyday speech. The first recorded mention of this register was around the 13th century, when it was distinguished from the throat and the head voice (pectoris, guttoris, capitis -- at this time it is likely head voice referred to the falsetto register. The speaking voice is named as "the chest voice" in the Speech Level Singing method. It is so called because it can produce the sensation of the sound coming from the upper chest. This is because lower frequency sounds have longer wavelengths, and resonate mostly in the larger cavity of the chest. A person uses the chest voice when singing in the majority of his or her lower range.The tonal qualities of the chest voice are usually described as being rich or full, but can also be belted or forced to make it sound powerful by shouting or screaming.Use of overly strong chest voice in the higher registers in an attempt to hit higher notes in the chest can lead to forcing. Forcing can lead consequently to vocal deterioration.

In falsetto, the vocal folds, or cords when viewed with a stroboscope are seen to be blown apart and a permanent oval orifice is left in the middle between the edges of the two folds through which a certain volume of air escapes continuously as long as the register is engaged (the singer is singing using the voice). The arytenoid cartilages are held in firm apposition in this voice register also. The length or size of the oval orifice or separation between the folds can vary, but it is known to get bigger in size as the pressure of air pushed out is increased. The folds are made up of elastic and fatty tissue. The folds are covered on the surface by laryngeal mucous membrane which is supported deeper down underneath it by the innermost fibres of the thyro-arytenoid muscle. In falsetto the extreme membranous edges, ie the edges furthest away from the middle of gap between the folds appear to be the only parts vibrating. The mass corresponding to the innermost part of the thyro-arytenoid muscle remains still and motionless.Some singers feel a sense of muscular relief when they change from chest voice to falsetto.In women, the falsetto voice refers to the whistle register.Generally when singers describe their range they exclude the falsetto voice. A classical male singer who routinely sings using the falsetto is called a countertenor. Countertenors tend to count this range. If a singer makes frequent use of their falsetto it may be counted as part of their vocal range.

The head register is used in singing to describe the resonance of singing something feeling to the singer as if it is occurring in their head. It's mentioned in the Speech Level Singing method used in some singing. All voices have a head register, whether bass or soprano. It is not associated with any particular musical pitch, but rather with the resonance of the voice in the head. The head register is sometimes called "the mask" by vocalists and singers because resonation from the voice is felt in the sinus cavities behind and around the eyes and nose. But often explanations for the physiological mechanisms behind the head voice alter from voice teacher to voice teacher. This is because, according to Clippinger: "In discussing the head voice it is the purpose to avoid as much as possible the mechanical construction of the instrument".

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