Good Tone Production for Singing

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What Is Good Tone?

Ideal tone is balanced (between all the resonating cavities of the vocal tract), free flowing (free from tension and constrictions), resonant (with all the overtones present and a “ring”), pure (the timbre is not made to be something that it isn’t naturally), and supported (by good, steady breath pressure). It is characterized by clean vowel definition and a balancing of qualities often referred to as “focus”, “ring”, “ping”, “placement”, “depth”, “roundness” and “warmth” to produce a complete voice in which all appropriate resonance factors are present in the singing voice.

When freedom of breath application, unhampered laryngeal response, and resonator configurations are in accord with each other, desirable tonal balances exist. (This combination of ideal characteristics is what defines flow phonation.)

Although we do not hear our voices as others hear them, most singers are capable of differentiating among sounds and thus analyzing the quality of their own vocal tone. Sensation associated with the chiaroscuro tonal balance is identifiable, repeatable, and above all, freedom-inducing. Hearing and seeing the ideal tone becomes a reliable means of self-monitoring, and the student’s goal should be to develop an awareness of his or her own body. The student of voice needs to consider how the voice sounds, how it feels and how it looks (e.g., vocal posture, such as position of the jaw and tongue, alignment of the head over the shoulders, etc. when seen in a mirror).

All singers are individuals. Therefore the sensations that one singer might experience during singing may not be felt in the same manner by another singer. Although I will often describe to my students what I feel as I’m singing, I always make sure that they understand that they may not feel the exact same sensations in the same areas of their bodies, nor describe them in the same manner as I do. Technical complications could arise within my students if they strive to achieve the sensations that I do.

Learning to recognize the new sensations experienced during well balanced singing ideally leads to a replacement of previous faulty perceptions. Sometimes, students need a little extra help in learning to recognize when they are singing with good, balanced tone. I will often have my students sing individual notes throughout the chromatic scale and have them attempt to alter their focus or placement - this usually involves making conscious and deliberate adjustments of the vocal tract, allowing the tone to become more nasally, then more breathy, then more centered - until I hear a resonant “ring” in their voices. I will then draw the students’ attention to their vocal quality at that point, and have them make a mental note of both the sensations and the sound experienced when their tone is good.

Generally, after students achieve and identify a tone with ideal resonance balance, I will ask them to describe the sensations, including the locations at which they occur. Describing these sensations in their own words helps them to memorize where and how sensations are felt. They then gain an effective self-monitoring checklist that will later help them to repeat the same methods for creating the same, ideal balanced tone. In time, the students learn to both recognize and reproduce this balanced tone immediately at the onset of sound, without having to make adjustments mid-way.

The results of correct, healthy tone production (and correct and effective use of the resonating cavities of the body) include a more pleasant sound or tone, an extended range, especially in the higher end, better control of breath and thus more vocal stamina (e.g., the ability to sustain notes for longer and sing longer phrases without the need for breath renewal), increased volume due to improved resonation, smoother vocal registration, improved vibrancy (often accompanied by a subtly shimmering naturally occurring vibrato), more physical comfort, and a healthier vocal apparatus due to less stress and strain.

Flow Phonation

The most desirable regime for singers involves singing with a flow phonation, (sometimes called free-flow phonation), which enables them to generate the maximum sound without risk of damaging the voice. Flow phonation refers to appropriate levels of airflow - breath is never consciously held back at the laryngeal level, the vocal folds offer sufficient resistance to the exiting breath, etc. - that match the requirements of the task at hand. For example, degrees of breath energy may alter continuously during singing as the demands and dynamics of a song may change from section to section, yet the goal of the singer is to maintain “freedom” of the voice at all times.

Flow phonation describes the process that permits the chiaroscuro tone. In addition, it is characterized by a high level of upper partials in the voice source spectrum. These upper partials contribute to the voice’s overall quality. Without them, the voice sounds almost one-dimensional and dull (or shrill, depending on the pitch).

In the case of flow phonation, for which a relatively low sub-glottal pressure is combined with a strong flow pulse and a high overall energy level, the maximum energy can be transferred to the voice. Flow phonation is characterized by a shorter closed quotient (a measure of the amount of times that the vocal folds are together as a proportion of the entire open/closing cycle) than pressed phonation, but it is longer than the closed quotient typical of breathy phonation. Flow phonation encourages a higher fundamental frequency amplitude in the voice source spectrum than pressed phonation.

Timbre

Vocal timbre refers to the quality or colour of tone being produced by a singer. Often qualities of timbre are described by analogy to colour or texture (e.g. bright, dark, rough, smooth, etc.). Describing a voice as “warm” or “shrill”, for instance, would also be making a statement about that particular voice’s timbre.

Vocal timbre can be effected or influenced by numerous factors. What the ear perceives as colour or quality is really a Gestalt impression of the voice that is reflective of the entire sound, and seldom as a function of its analytic or separate components (all the properties of tone). The physical characteristics of sound that affect and create the perception of timbre include spectrum (the richness of the sound or tone, sometimes described in terms of a sum of a number of distinct frequencies, or overtones and envelope (the overall amplitude structure of a sound, which includes attack time, decay, sustain, release, transients, etc.).

Vocal timbre is part of what makes some voices suitable for soloing or lead singing and other voices more suited to singing in groups or choirs, while still other voices are more suited to shower stalls.

Chiaroscuro timbre is a voice-pedagogy term that is used universally to refer to the balancing of the light or clear (chiaro) and dark (oscuro) aspects of timbre, or balancing tonal brilliance and depth of the resonance. In vocalism, it specifically refers to the equilibrium of acoustic strength manifested by an ideal distribution of lower and upper harmonic partials (overtones), clustered in formants. Specific balances among the formants are characteristic of the resonant voice of premier singers, regardless of vocal category. That is to say, the chiaroscuro timbre of the classic international school demands balance among the prominent areas of acoustic strength, the fundamental and the first, third, fourth, and fifth formants. (This balance has been confirmed by spectrographic analysis.)

Every vocal instrument has its own individual quality, but all timbres must adhere to the chiaroscuro principle. Good singers are able to avoid “noise” elements that are non-integers of the fundamental frequency. Acceptable timbre will display predictable relationships between the first, second, third, fourth and fifth formants, without by-noises. (Please read the article on Vocal Tract Shaping for more information on how to adjust the formants of the voice in order to achieve better tone.)

The nature of the vocal instrument itself does not need to be altered to produce advantageous harmonic integration. False manipulation of a voice to either augment or diminish the balance between breath application, laryngeal response, and resonator configurations will not produce a commendable outcome. Instead, the quality of the tone will be diminished.

Formants

The term formant refers to peaks in the harmonic spectrum of a complex sound, such as the human voice, that is produced by some sort of resonance. This area of acoustic strength results from the cumulative distribution of upper harmonic partials, which are also known as harmonics (integer or whole number multiples of the fundamental frequency of a tone – the lowest frequency of a complex sound, which corresponds to the unique pitch heard in such a complex tone) or overtones.

Partials that are not multiples of the fundamental frequency produce what is called noise in the singing voice.

Formant regions are not directly related to the pitch of the fundamental frequency and may remain more or less constant even as the fundamental changes. If the fundamental is well below or low in the formant range, the quality of the sound is rich. However, if the fundamental is above the formant regions the sound is thin and often shrill in quality and, in the case of vowels, may make them impossible to produce accurately. (This is part of the reason why singers often seem to have poor diction, or their vowels are indistinguishable, on very high notes.)

Formants are essential components in the intelligibility of speech (e.g., different sustained vowel sounds are distinguishable because of the differences in their first three formant frequencies). In other words, formants define, or help us to distinguish between, vowels. Producing different vowel sounds amounts to “retuning” these formants (by shaping the vocal tract in specific ways) within a general range of frequencies. If, as the mouth opens naturally with rising pitch and amplitude, the integrity of the vowel is retained, the first formant will grow in strength and there will be no loss of upper harmonic partials (“ring”). Resonance balance will pertain throughout the scale.

Formant frequencies are determined largely by the shape of the vocal tract (the cavity where the sound that is produced at the sound source – the larynx – is filtered), which is able to produce a highly variable structure of overtones. For instance, opening the jaw, which constricts the vocal tract toward the glottal end and expands it toward the lip end, is the deciding factor for the first formant. This formant frequency rises as the jaw is opens wider. The second formant is most sensitive to the shape of the body of the tongue, and the third formant is most sensitive to the tip of the tongue. Therefore, as the tongue shape changes to produce a different vowel, the formant frequencies will also change.

Swedish physician and medical researcher in the area of human physiology, Johan Sundberg, identified an extra formant in the range of 2500 to 3000 Hz, or concentration of intense acoustic energy, between the third and fourth formants – which he called the Singer’s Formant – that is present in the frequency spectrum of trained singers but absent in speech and in the spectra of untrained singers. Developed through vocal training and created by the special resonance of the vocal tract when the larynx is lowered, the Singer’s Formant produces the “ring of the voice” that enables a singer’s voice to be heard and understood over an orchestra. The classically trained singer strives to develop a Singer’s Formant that enhances the overall richness and ringing in his or her voice.

The Singer’s Formant ideally consists of strong third, fourth and fifth formants. It is produced by the frequencies of the third, fourth and fifth formants of the singing voice moving so close to each other that the resulting cluster appears as a prominent, consolidated region in the frequency spectrum of the voice. The potential strength of the Singer’s Formant depends on voice category, being somewhat weaker in basses than in tenors, and altogether questionable in sopranos. (The relative intensity of a soprano Singer’s Formant is lower than those of other voice types. Additionally, it has a different shape, being higher and wider as compared to that of the alto, and is split into two peaks – one in the range of 2.5-3.5 kHz and another between 3.3 and 4.3 kHz. It is unclear as to whether each peak contains only a single formant, as in an untrained singer’s voice, or whether one of the peaks contains two formants, which would indicate the presence of a Singer’s Formant.)

The articulatory way to achieve the Singer’s Formant lies through dilation of the pharyngeal opening so that it becomes wider than the tracheal opening. This happens if a dilated pharynx is combined with a low laryngeal position.

A lot of contemporary singers believe that they don’t really need to know anything about formants. The science seems too complicated, and they are under the impression that the information will help them little in their singing. They would rather have their teachers use different, more seemingly practical methods (e.g., giving illusory descriptions of acoustic events) for explaining chiaroscuro balance in the singing voice. Although scientifically based, the concept of formants can be learned by anyone of average intelligence. It may not be necessary to memorize the frequencies of pitches (numerical values) and the specific harmonic content of each vowel, but it is beneficial to the student of voice to be equipped with a basic understanding of what formants are and how they affect overall tone. One especially important reason for studying formants is to gain a better understanding of, and thus be able to take advantage of, the relationship between articulation and vocal tract resonance. Information will enhance, not detract from, learning.

(I will explain the relationship of vowel formation to formants a little more in-depth in my upcoming article on Singing With An Open Throat: Vocal Tract Shaping. My article Anatomy of the Voice on this site has additional information about formants, as well.)

Vocal Resonation

Vocal resonation is the process by which the basic product of phonation – voiced sound, which is the buzzing sound produced by the vibrations of the vocal folds - is enhanced in timbre and/or intensity by the air-filled cavities through which it passes on its way to the outside air. Resonance, therefore, is voiced sound that is amplified and modified by the vocal tract resonators (the throat, mouth cavity, and nasal passages), and is the result of an acoustic alliance between vibrating bodies at an identical fundamental pitch.

The strength of tone must be gained not only by good, steady breath pressure (see The Role of Breathing in Tone Production below) but also by the focal point on the palate, by the complete utilization of the palatal resonance. In other words, tone quality is determined or enhanced by the way in which a singer uses his or her vocal resonance. The end result of resonation is, or should be, to make a better sound. Therefore, a key factor in achieving good, balanced tone is mastering use of resonance. Every singer needs to train the voice to distribute the sound into the three cavities in a balanced manner.

Singing involves the utilization of more of the supraglottic (above the glottis) spaces for resonance than does speaking, and the vowels are prolonged. Otherwise, speaking and singing are almost identical.

Resonance can be either sympathetic or forced. The sounds of singing are the result of sympathetic resonance. This sympathetic vibration is not to be confused with resonance, which is restricted to the vocal tract – the open chambers, not the bony structures - conjoined with the nasal cavities only for nasal phonemes.) For instance, the cartilaginous external nose, as well as the bony structures of the skull (sinuses, cheeks, foreheads, occipital bones, etc.), can be set into sympathetic vibration - bone is a remarkable conveyor of sympathetic vibration - but not into actual resonance because they are not resonators; they do not contribute to the complex tone that the listener hears and cannot contribute to the actual resonance of the voice. However, the resonator filtering of laryngeal tone includes only the areas that are open cavities.

For example, although a misnomer, chest voice is named such because many singers feel a sensation of resonance in the chest cavity. In this case, sympathetic vibration is conveyed by bony and cartilaginous parts of the sternum and rib cage. Of course, it is not resonance itself that is felt in the face or head. Rather, it is sympathetic vibrations that are felt, since the bones of the face conduct the vibrations of sound bouncing off the hard surfaces.

This does not preclude the fact that singers often feel sympathetic vibratory responses in one or more areas of the body. Indeed, the sensations that are produced by sympathetic vibrations are realistic to the singer, and they may become reliable indicators of resonance balance. However, the registering of sympathetic vibration, or the perception of resonance, is highly individual and can be experienced only personally. Sympathetic vibration during singing varies greatly from person to person. Therefore, to expect everyone to experience the same sensations while singing is both unrealistic and unwise.

Placement of the voice generally describes both how the vibration of the air column interacts with the resonating structures of the body to accentuate or diminish the size of the formant and where one feels the augmented vibration due to the change in the relationship of the formants to areas of the body. For most singers, placement is used to describe where they feel the sympathetic vibrations most. For example, head voice is so-named because most of the resonance is felt on the bony surfaces of the face or head. (Some techniques refer to this area as the “mask”, or "masque”.)

Much of what singers may describe as placement is really sympathetic vibration. The sensations associated with sympathetic vibration help the performer monitor the sounds of singing. When the spectral balance is complete, a singer is aware of sensations in the bony structures of the head, throat or chest that are quite different than those of imbalanced phonation. Once an association with ideal sound has been established, these proprioceptive sensations become dependable indicators of tonal balance.

For some singers, the notion of placement suggests that they can direct the resonance of their voices. However tone, which originates in the larynx, can’t actually be placed, so attempts at placing the voice or inducing sensations in specific parts of the body are generally considered to be futile.

One example of placement lingo is the concept of “forwardness”, which denotes the idea of keeping the tone placed in the front of the face, or “singing through the mask”, or imagining the voice as a line in front of the face. Some teachers avoid talking about placement or forwardness of tone because they are subjective terms that don’t take into consideration the individual experiences and sensations associated with singing. These same instructors may also fear that their students will focus too much on producing the buzz of resonance and, in turn, induce tensions.

Furthermore, teaching the concept of forwardness may also be somewhat counterproductive, if not dangerous, because certain forms of sympathetic vibration felt in the mask are actually the product of undesirable timbres. Hypernasality, for example, may produce a great deal of sensation in the nasal cavity, but it is not representative of good, balanced tone. Being instructed to place tone may exacerbate existing technical problems, if not create new ones.

Rather than speaking of placement, it may be preferable to make certain that buccopharyngeal resonator shapes properly match laryngeal configurations. (I will be discussing how to balanced tone in more detail in the upcoming companion to this article entitled Singing with An Open Throat: Vocal Tract Shaping.) However, I find that talking about the notion of forward placement can be a useful imagery tool for some, more “visual” students – as it was for me in my vocal training - so long as they are equipped with correct information about acoustical science.

After experiencing the presence of sympathetic vibration that results from efficient resonance balancing, students can develop their own imagery or subjective terminology that can then be utilized and reinforced by the teacher during their private lessons. The goal in studying voice, ultimately, is to learn to produce a good resonance balance, and each student may take a different path to finding his or her ideal tone.

(For more detail about resonance, read my article on the Anatomy of the Voice.)

'Projection'

There are some voice instructors, musical theatre professors and choir directors who teach the concept of “projection” as a means of increasing volume so that the voice may be heard better by an audience.

This philosophy that the voice needs to be “projected” can lead to bad technique, however, as it tends to conjure up mental images (i.e., throwing the voice to the people in the back row, etc.) that are followed by vocal habits (e.g., opening up the mouth excessively, like a “horn”, etc.) that aren’t usually very healthy, neither psychologically nor physically. Even if supported by diaphragmatic breathing, this technique can be injurious to the vocal instrument. While it is true that the buzzing sound created by the vocal folds needs to resonate effectively off the hard surfaces of the vocal tract, be shaped, and then escape through the mouth, the notion of having to project the voice tends to lead to vocal health problems including tension, strain and injury, as well as a diminished air supply (and thus less stamina), because an excessive amount of air is being forcibly pushed out of the lungs and past the vocal folds.

When singers are told to project, they often feel the need to shout in order to make their voices sound louder. However, shouting, or actively increasing volume beyond natural, comfortable levels, does not necessarily create more carrying power, as natural resonance is often lost. In fact, pushing merely distorts resonance. Instead, it is the correct shaping of the vocal tract in order to maximize resonating space and increase the strength of the vocal formants that makes the voice more audible in a theatre or concert hall. Articulation and diction (enunciation) play a key role in creating more effective resonation because they ensure that ideal acoustical configurations of the vocal tract are assumed. (I will be discussing vocal tract shaping in more depth in an upcoming follow-up to this article entitled Singing With An Open Throat: Vocal Tract Shaping.)

Instead of thinking in terms of getting more sound out, or making the voice louder by increasing volume, a singer should focus on achieving a balanced, fully resonant tone, which will carry itself without the need for pushing or shouting. When resonance is ideal, the voice will be heard, and it will be healthy.

It is my belief that it would be in the best interest of vocal students everywhere for teachers and directors to remove the term “projection” altogether from their vocabulary.

Why Our Voices All Sound Different

Everyone singer has a natural, unique sound, although some voices are more distinctive than others (e.g., Alanis Morrissette, Amy Whinehouse, Michael Jackson, etc.). Some singers have unmistakable qualities in their voices, such as “richness”, “warmth”, “depth”, “relaxedness”, “maturity”, “bluesy-ness”, “thickness”, “sultriness”, etc. that make them instantly recognizable to the listener and set them apart from the crowd, or the rest of the choir at the very least.

Although we can effect some change on our natural timbre, doing so comes with both the possibility of creating an imbalanced, worsened tone and the risk of potential harm to the vocal apparatus through the development of bad technique and unhealthy habits. Our voices seem to be better and more naturally suited for specific sounds and timbres. Some voices are ideal for opera, while others are able to produce a grungy, heavy rock sound, for instance. (You can read about voice types, vocal classifications and vocal weights in the Glossary article on this site. The definitions listed there provide further information about the different types and qualities of voices that are common amongst singers.)

Our speaking and singing voices are created from the same anatomical structures. The respiratory system (lungs, diaphragm and abdominal muscles), laryngeal mechanism (vocal folds, laryngeal cartilages, muscles and nerves) and the supraglottic tract (the spaces above the vocal folds, including the back of the throat, mouth, nasal passages and sinus cavities) all work to produce our vocal sounds. (Please read Anatomy of the Voice for an overview of these anatomical structures that help to produce our voices. I will be including more detail about the anatomy of the vocal tract in my upcoming article about the open throat.) In general, voice characteristics are determined by the interactions of breathing mechanisms, the vibrating vocal folds and resonances of the vocal tract.

As mentioned above in Vocal Resonation, the human voice utilizes three resonant cavities to aid in the production of desired frequencies: the larynx, the mouth, and the nasal cavity. The different sizes and shapes of these cavities produce distinctive tonal qualities. There are few reasons why every singing voice sounds different, which includes the size of the vocal tract (larynx, pharynx, mouth, etc.), as well as other parts of the body, articulation (manipulation of the vocal tract and formant tracking) and use of resonance.

One deciding factor in how different voices sound is the fact that our vocal tracts (the distance from the larynx to the lips) have varying lengths, although the average of which is about four inches. Before puberty, the average speaking pitch and size of the larynx are about the same for both males and females. The lengthening and corresponding mass increase of the larynx that is brought on by puberty reduces normal average speaking pitches – the fundamental frequency of the voice, strongly related to the perception of the pitch of the voice.

Men, generally speaking, have larger vocal tracts, which essentially gives the voice a lower tonal quality, independent of the vocal folds themselves. The female's larynx typically will appear to have a little more space between the arytenoids than the male's larynx does. This is thought to be primarily an anatomical difference and secondarily a cultural difference. This glottal shaping helps to give the female voice a typically softer quality due to the corresponding airflow through the larynx.

Men and women have different vocal folds sizes; adult male voices usually have longer folds with more mass. The difference in vocal folds size between men and women means that they have differently pitched voices. Laryngeal size and structure play a significant role in determining a singer’s range. The greater the length and the vibrating mass of the vocal folds, the lower the fundamental frequency (the lowest frequency in a harmonic series) of pitch.

In addition to these gender differences, genetics creates variances amongst the same sexes – different singers will have different ranges and tessituras - which lead to voices being categorized into types. The singing voice is partly categorized by the range of fundamental frequencies that the person can sing in performance, as well as by the quality, agility, and how big a sound that particular voice can produce, referred to as vocal weight. The size and shape of a singer’s vocal tract will affect not only the singer’s range but also his or her registration change points.

The resonance frequencies of the vocal tract tend to emphasize a series of frequencies that relate to the vocal tract size and shape. The vocal tract is not a simple tube. Rather, it is a tube of varying sizes and shapes, and is highly adjustable. For this reason, it tends to emphasize some overtones of the phonated sound and de-emphasize others.

The sound of each individual's voice is entirely unique not only because of the actual shape and size of an individual's vocal folds and larynx, but also due to the size and shape of the rest of that person's body. Humans have vocal folds which can loosen, 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. Sound also resonates within different parts of the body, and an individual's size and bone structure can affect the sound produced by an individual.

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 functions are described as different kinds of vocal registers and phonatory modes.

In addition to these natural deviations listed above (i.e., the size and shape of the individual’s vocal tract and body), how singers pronounce their words has a lot to do with the uniqueness of their singing. How the vocal tract articulators (the tongue, soft palate, jaw and lips, all of which work together to produce recognizable words) modify the voiced sound that is created by the vocal folds is an important part of achieving balanced vocal timbre. The adjusting of the articulators affects the frequencies of the vocal tract resonances (formants), and thus how a listener hears vowels, as well as the overall tone of the voice. My upcoming article, Singing with An Open Throat: Vocal Tract Shaping will provide specific information on correct usage of the articulators in order to maximize resonance and balance tone.

Last updated on Fri Aug 5 22:02:33 2011