Vocal Registration

Vocal registration is the term used to denote various theories of how the human voice changes, both subjectively and objectively, as it moves through its pitch range.

Nearly all untrained voices have noticeable differences in timbre at different pitches. This is most easily seen in males, who are generally aware that they can speak in both their usual voice, which sounds "male," and in another, higher voice that is lighter, breathier, and sounds "female." Each of these timbres is referred to as a "register," hence "vocal registration." This is the clearest example, though it is also extremely common for singers who have recently begun studying voice formally to notice more subtle differences in their voice as they move through their vocal range.

Beyond these facts, it should be noted that registration is somewhat controversial, with disagreement on how many registers there are and indeed whether they exist at all. Further complication arises from the fact that registration is, broadly, unique to a particular singer and is to some extent subjective - a head note for a bass is a chest note for a soprano.
As mentioned above, registration is a controversial topic in vocal pedagogy. In this section, we outline the more popular theories of vocal registration.

Multiple Rigister Theory

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.

Speaking Voice (Chest)

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, see falsetto article) by the writers Johannes de Garlandia and Jerome of Moravia.
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.

It was discovered via stroboscope that during ordinary phonation, or speaking in a man the vocal folds contact with each other completely during each vibration closing the gap between them fully, if just for a small length of time. This closure cuts off the escaping air. When the air pressure in the trachea rises as a result of this closure, the folds are blown apart, while the vocal processes of the arytenoid cartilages remain in apposition. This creates an oval shaped gap between the folds and some air escapes, lowering the pressure inside the trachea. Rhythmic repetition of this movement a certain number of times a second creates a pitched note. This is how the chest voice is created.

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.

Falsetto

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.

Head Register

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.

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".

Other Theories

In addition to those detailed here, a variety of theories of register have been proffered. At the extreme, they may propose more than a dozen distinct vocal registers. Those listed above are the most commonly seen today. For an introduction to other theories, see Caldwell, 2001.