Resonation and Maintaining a Healthy Effective Voice

Resonation

Resonation

The buzz created by the vocal folds resonates (vibrates) the air column and this in turn causes the structures above and around the larynx to vibrate/resonate as well.

Remember from Phonation that the vocal folds vibrate and chop the air stream into little puffs of air. The rate or frequency at which these puffs come out is very fast - from 32 cycles per second or Hertz (Hz) for a very low bass to 3136 Hz for a very high soprano. We speak somewhere between 98 Hz and 262 Hz. This rate is called the fundamental frequency.

Almost anything can vibrate, and will vibrate at a natural frequency, that is at a rate that is most conducive to its vibrating. A good example of natural frequency can be seen on a backyard swing: no matter how hard you push the swing, the rate of frequency of swinging is the always same, no matter how far you travel each time. Another familiar example is the tuning fork. It vibrates most powerfully and the longest at its natural frequency. In the same way, the various structures and tissues of the body, resonate more easily at certain pitches.

You can feel this by tilting your head back and saying, in a low voice, "Awwwww". Put a hand on your chest and feel it rumble. Now tilt your head forward, place a hand on your head and say, "Heeeeeeeeeee" in a high voice. Feel the vibrations in your skull?

The parts of the body that can vibrate in harmony with the voice are often called Resonators.

The Air Column

Extending from your larynx to your lips, the air column vibrates at a natural frequency - in much the same way that the pipes of an organ do. As you shorten the organ pipe, and thus the air column, the pitch gets higher.

Try blowing across a bottle and then adding water and blowing again - observe how the pitch rises.

In speech, the rate of vibration of the vocal folds creates the fundamental frequency, or pitch of the the sound. The frequency or frequencies at which the air column vibrates determines the quality of the tone.

The sound created by the vocal folds isn't a pure tone - it is complex. It is made up of the fundamental frequency (the rate at which the folds vibrate) and a number of partials, which are harmonics of the fundamental frequency, vibrating 2 times, 3 times, 4 times, etc... as fast as the fundamental. Our voices are made up of a spectrum of the fundamental and these "overtones".

What we recognize as "vowels" are actually changes in the quality of the tone. Our tongues allow us to change the shape of the "tube", specifically changing the cross-sectional "width" by sliding forward or back.

Move your tongue forward into an [i] /"EE" (as in "reed") position: feel how your mouth is narrowed by your tongue just behind your teeth?
Try shortening it by pulling back into an [u]/"oo" (as in "mood"): the tongue is pulled back here. (Notice how the degree of lip-rounding also affects the sound?)
Try going back and forth from "EE" to "oo", keeping the same pitch throughout. As you tongue slides back towards the "oo" you may hear how part of the sound drops in pitch, even though your F0, fundamental frequency remained the same.

Lip-rounding essentially lengthens the tube, modify the first, F1 formant. (The middle of our tongues primarily shape the F2 formant, and our tongue tips shape the F3 formant.

You can hear you that by saying "uh" and "er", lifting and lowering your tongue tip.

Resonators

The following areas vibrate "sympathetically" with the air column. The way in which each area vibrates acts as a cue to the quality of the sound created, giving tactile motor feedback to the brain, which works in conjunction with the hearing mechanisms.

What is perceived or described by voice teachers as "placement" of the voice, generally describes how the vibration of the air column interacts with these structures to accentuate or diminish the size of the second and third formants ( F2and F3 ). The term "placement" indicates where one feels the augmented vibration due to the change the relationship of the formants to areas of the body.

The following is a list of Resonators and the pitches or vocal qualities that most easily activate them
Chest and Lower Body - low pitches and open sounds ("AW")

Throat - mid-range, easy speaking tone

Mouth - upper mid-range, mid-vowels

Nasal - close, front vowels, especially when followed by a nasal consonant

Facial - high range, front vowels

Sinus - given that there are so many sinuses, many different quality sounds activate them

Bones of the skull - falsetto, very high range, closed vowels.

http://www.yorku.ca/earmstro/journey/resonation.html

http://www.thefreedictionary.com/resonation

Maintaining a Healthy and Effective Voice

Tips to prevent voice problems

Stay hydrated:
Drink plenty of water. Six to eight glasses a day is recommended.
Limit your intake of drinks that contain alcohol or caffeine, which can cause the body to lose water and make the vocal folds and larynx dry. Alcohol also irritates the mucous membranes that line the throat.
Use a humidifier in your home. This is especially important in winter or in dry climates. Thirty percent humidity is recommended.
Avoid or limit use of medications that dry out the vocal folds, including some common cold and allergy medications. If you have voice problems, ask your doctor which medications would be safest for you to use.

Maintain a healthy lifestyle and diet:
Don't smoke and avoid second-hand smoke. Smoke irritates the vocal folds. Also, cancer of the vocal folds is seen most often in individuals who smoke. 

Avoid eating spicy foods. Spicy foods can cause stomach acid to move into the throat or esophagus, causing heartburn or GERD. 

Include plenty of whole grains, fruits, and vegetables in your diet. These foods contain vitamins A, E, and C. They also help keep the mucus membranes that line the throat healthy. 

Wash your hands often to prevent getting a cold or the flu. 

Get enough rest. Physical fatigue has a negative effect on voice. 

Exercise regularly. Exercise increases stamina and muscle tone. This helps provide good posture and breathing, which are necessary for proper speaking. 

If you have persistent heartburn or GERD, talk to your doctor about diet changes or medications that can help reduce flare-ups. 

Avoid mouthwash or gargles that contain alcohol or irritating chemicals. If you still wish to use a mouthwash that contains alcohol, limit your use to oral rinsing. If gargling is necessary, use a salt water solution. 

Avoid using mouthwash to treat persistent bad breath. Halitosis (bad breath) may be the result of a problem that mouthwash can't cure, such as low grade infections in the nose, sinuses, tonsils, gums, or lungs, as well as from gastric acid reflux from the stomach.

Use your voice wisely: 

Try not to overuse your voice. Avoid speaking or singing when your voice is hoarse or tired. 

Rest your voice when you are sick. Illness puts extra stress on your voice.

 
Avoid using the extremes of your vocal range, such as screaming or whispering. Talking too loudly and too softly can both stress your voice. 

Practice good breathing techniques when singing or talking. Support your voice with deep breaths from the chest, and don't rely on your throat alone. Singers and speakers are often taught exercises that improve this kind of breath control. Talking from the throat, without supporting breath, puts a great strain on the voice. 

Avoid cradling the phone when talking. Cradling the phone between the head and shoulder for extended periods of time can cause muscle tension in the neck. 

Consider using a microphone when appropriate. In relatively static environments such as exhibit areas, classrooms, or exercise rooms, a lightweight microphone and an amplifier-speaker system can be of great help. 

Avoid talking in noisy places. Trying to talk above noise causes strain on the voice.
Consider voice therapy. A speech-language pathologist who is experienced in treating voice problems can teach you how to use your voice in a healthy way.

http://www.nidcd.nih.gov/health/voice/pages/takingcare.aspx