Anatomy and Physiology Series: Physiology of Exhalation (and breath support)

You may have heard that we don't really use all the air our lungs take in. This is very true.  In fact, pulmonologists and other folks concerned with the health of the respiratory system have come up with several volumes to determine healthy lung function.  


Let's go over some of these volumes so you'll have some idea of what I'm talking about when I refer to them:  Tidal volume (TV) is the volume inhaled and exhaled during one cycle of respiration.  It varies from resting to exercise and age of person, etc.  Inspiratory reserve (IRV) is the air inhaled beyond the tidal inspiration.  Expiratory reserve (ERV) is the air expired beyond tidal expiration.   Vital capacity (VC) is the one most often referred to in voice research.  VC is the volume available for speech.  It is a combination of IRV, ERV, and TV.  (Others we won't talk about are:  Residual volume (RV) is the air that remains in the lungs after maximum expiration...it's always in there.  Functional residual capacity (FRC) is the air that remains in the body after passive exhalation, inspiratory capacity (IC) is the volume that can be inhaled from resting lung volume, and total lung capacity (TLC)  which is the sum of all lung volumes.)*


During respiration, the forces of exhalation are passive if we stay above 38% of our VC. However, when we speak professionally and sing, we have to maintain fairly consistent subglottal pressure (which we'll get to in detail later) while going beyond that 38%.  Not only that, but we have to slow our exhalation prior to getting beyond that 38%.*  So how do we do all of that?  By using a combination of our checking action combined with our musculature of forced exhalation.


Checking action* is the process by which you check (or hold back) the flow of air out of your inflated lungs by means of the muscles of inhalation.  When singers heighten this and expand it to singing, they call this the appoggio technique.  It is a natural occurrence during speech, and is especially noticeable during public speaking.  (It is no wonder those pedagogs of the "golden age of singing" came up with this as a key to proper singing.  It's a coordination that is already there!)  It's built into the healthy-functioning adult body by the biological respiratory system responding to the communication demand the brain is putting on it.  Singers need to improve this coordination, making it the most effective possible and using even more muscular energy to sustain even longer phrases of communication (i.e. music.)  I have found that training this natural coordination will inherently involve a student going a little too far with the coordination, either resulting in too little air flow into the throat and/or too much air flow, but I think that is a natural process of heightening this coordination to meet the demands of singing.  Once a singer acquires this more precise coordination, it really just happens "in the background" of his/her brain as long as they actively maintain the muscular strength through constant usage (ala the professional singer with consistent practice habits.)  One of the abilities of a great teacher is to know when a student needs more strength/coordination training and when that student needs to back off of conscious control of the coordination to allow it to become "second nature."  (If you don't ever "back off," I believe you are in danger of eliciting a different coordination discussed below.) 


Exhalation musculature is actually only used when expiratory reserve needs to be tapped into.  When you get below the 38% point of VC during speech/singing, your body will call on its muscles of forced exhalation to push beyond that point so that we can keep right on going.  This action occurs sequentially along with the checking action to utilize all of your expiratory reserve before your next breath, if necessary.  


This coordination of checking action, with forced exhalation taking over at the appropriate point, takes a lot of muscular effort when sustained for a long period of time...as when the teacher lectures for an hour, the actor performs a two-hour play, or the singer sings for the two hour opera.  That is why we need to train in the strength and endurance for this coordination!


However, within our training there is a biological function that we need to be aware of so that we can counter it's effects.  This is called abdominal fixation* and it is the process of holding air in the thorax to stabilize the torso.  (This is what results in "grunting" when you're lifting that heavy couch while helping your friend move.)  It is a biological function that occurs when the body needs more rigid support and comes from the action of abdominal contraction along with full glottal closure to "hold" the air in the lungs.  It is the action that makes your chest and torso inflexible for more strength.  (This is also why your exercise instructor will remind you to "breath" during weight lifting and/or abdominal crunches and/or strenuous workouts.)  If you're brain tells your torso you need some major "support" for the task at hand, this is the coordination that your brain will naturally tell your body to do.  Obviously, closing off the laryngeal opening completely does not bode well for the singer, and it is exactly this motion that, I believe, lends itself to "pushing" the voice.  How do we counter it?  Well, I think a conscious realization that, since we're trying to maintain continuous breath flow, it must be a system that is capable of moving.  It must be able to make minute* adjustments to our air flow upon command, and therefore, it must retain a certain amount of flexibility.  It's not an abdominal "crunch," it's a belly-dancer's stomach "roll"...sorta-kinda.


So how do we train good breath support for singing?  I believe it must be based in the natural support mechanism we already use for sustained speech.  We must strengthen that mechanism to build our endurance and checking action while not encouraging the abdominal fixation of "rigid" support to creep in a close off our laryngeal system altogether.  So this is where we get the idea of strong, yet flexible support.  Some aspects will be rigid:  Such as our inhalation muscles of the upper back and our exhalation muscles of the lower back.  These guys will stabilize the torso while the other muscles of inhalation and exhalation do their work of checking and forcing exhalation at the appropriate moments.  It is a delicate balance, it is incredibly frustrating to figure out, but if you accept that it is not a completely foreign bodily function, then it might just work itself out faster than you think. 




*Just how minute the changes are that are required will be gone over during the laryngeal physiology.  So in the meantime:  Prepare to have your mind blown!  (Maybe...well...it blows my mind at least!)*


*Citation:  Seikel, J. A., King, D. W., & Drumright, D. G. (2010). Anatomy and physiology for speech, language, and hearing. Clifton Park, NY: Delmar.