reVoice

Riva Capellari

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Located in Brookside in the heart of Kansas City

News of Note July 2012

Innervations……
Did you know that highly skilled singers can sing seven to nine different pitches in the course of about 1 second? Either did I! After all these years of teaching and singing, this news was a surprise, even to me. But it just reconfirms that the voice is an amazing instrument. So let’s continue to explore its many facets, segueing from last month’s introduction to phonation to a more in depth look at a specific system of the human body as it relates to vocal production.

In the June issue, we just touched on the role of the neurological system in vocalization. This month, we will identify the nerves that innervate the laryngeal muscles and how they assist in the business of music making.
There are basically two types of neural control: voluntary and reflexive. In singing, the voluntary control regulates movements prior to phonation. It configures the vocal folds such that they produce the sound we are hearing in our heads. It also sends messages to the respiratory system to power up the right amount of subglottal air pressure necessary for initiating vocal fold vibration. This prephonatory set up occurs 50-500 thousands of a second before the onset of the sound and is activated when we take a breath. Our brain speaks to the muscles through our nervous system to match the on-coming air pressure to the vocal fold positioning to produce the most efficient and effective tone possible. This set up helps determine pitch, intensity and even vocal tone color.
Reflexive vocal motor functions are intra-phonatory, that is, they take over after phonation has begun. Sustained phonation requires continuous adjustments to the tension and length of the vocal folds to facilitate pitch changes. In the meantime, the amount of air pressure must be monitored to meet the demands of varying levels of intensity and resistance to the constantly changing vocal folds. A good example of this was given in last month’s issue regarding the balancing act between the CT (cricoidthyroid) and TA (thyroidarytenoid) muscles. They work together to maintain pitch when air pressure rises in an effort to increase volume. A change in one parameter often creates a domino-like effect, necessitating changes in other areas to produce an even, well produced tone.
In effect, the actions of reflexive control reflect the abilities and learned skills of the singer, what is sometimes referred to as vocal technique. It is similar to the pianist or guitarist who can play their instrument without looking at their fingers – the fingers automatically (reflexively) know where to go.
The muscles of the larynx are capable of moving within a wide range of speeds (the larynx has the second fastest muscles in the body – can you guess the first? Hint: it is linked to our protective survival instincts).* They have the capacity for great flexibility, to produce strong singing and build up resistance to fatigue.
The laryngeal muscles are innervated by two major nerves: the surperior laryngeal nerve (SLN) and the recurrent laryngeal nerve (RLN). Both branch off from the vagus nerve, the 10th cranial nerve in the brain.
The left and right sections of the SLN innervate only the CT muscle. Remember, this muscle is responsible for stretching the vocal folds enabling us to sing higher. The RLN communicates with all the other internal laryngeal muscles. The left branch of the RLN loops under the aorta before returning to the larynx – hence its name – making it longer than its counterpart on the right. Damage to either of these nerves from surgery or physical injury can be devastating to the voice, especially for professional singers.
The neuromuscular motor network is tied into sensory receptors, establishing a feedback system to the brain enabling it to guide vocal co-ordinations via these reflexive actions. These unconscious modifications take place in the laryngeal muscles and are triggered by “high speed sensory input” sent by sensors in the tissues of our larynx and surrounding areas. The internal branches of both the SLN and the RLN also contain sensors for this purpose. These status reports provide our brain with information it then communicates to our neural motor system as to what on-going adjustments are needed to continually match up what our “inner ear” (our brain) is wanting to hear (produce).
So how does this information help us to become better singers? Considering that the foundation of reflexive neural control is based upon our learned abilities, much of vocal training involves building and maintaining skills that will keep us in good stead as we sing. If our technique is solid, we can turn over the voluntary control to the automatic or reflexive control and, as singers, enjoy and share the emotional and intellectual connection we have to the text and music. If either or both of these neural control systems are deemed faulty, the vocal tone and the intonation will suffer along with the quality of communication between singer and audience.
Well-conditioned laryngeal muscles are also essential to good singing if we want our neural control systems to be able to accomplish their jobs. So it is important, as vocalists, we understand how our motor AND sensory neural systems work, how to improve and maintain them and how we can use them to create beautiful music!
*the eyelids!

Songs Days of Summer
On Sunday, July 22nd, at 2pm, reVoice is offering an informal singing experience in a comfortable and friendly atmosphere. Bring a favorite song to sing. The cost is $20 and includes an accompanist and refreshments. Enrollment is limited so don’t miss this one and only summer vocal gathering! Go to www.revoice.biz and click on the services page for more details and the registration form.
Vocal Gifts
Gift certificates from reVoice are available all year long, not just during the holidays. Consider surprising that special someone with a unique gift of music. These certificates range in price from $25 to $80 and can be used towards private or class sessions. Just contact [email protected] now to order!
Summer Time Out
Voice classes have come to an end for the summer. They will resume in September. Stay tuned for details! However, private lessons are still available through the end of July, so if you have always wanted to try out singing lessons, this may be the summer to “re-discover” your voice!

Photo – svpow.com The Science of the Singing Voice. Johan Sundberg. Northern Illinois Univeristy Press.1987. Your Voice: An Inside View. Scott McCoy, DMA. Inside View Press. 2004. Bodymind and Voice: Foundations of Voice Education, Vol 2. L. Thurman, EdD & Graham Welch, PhD, co-eds. The Voice Care Network. 2000.

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