Voice

Have you ever wondered how your voice works? What is “normal” vocal function and what contributes to difficulties in using your voice effectively for speaking or singing?

The foundation for my training as a Speech Language Pathologist is understanding the anatomy and physiology related to ALL facets of communication… including vocal production.

Four “systems” contribute to efficient vocal function: Respiration, Phonation, Resonance, and Articulation. As well as considering how these systems support voice production, it is important to also understand that voice production is actually a “secondary function” for these systems. How can that be? Here is a summary of the “primary functions” of these systems and how they contribute to voice production:

• Respiration (lungs, diaphragm, ribs, trachea, vocal cords):

  • The primary functions of breathing are to replenish the oxygen supply our bodies need and to remove carbon dioxide. These functions are life sustaining!

  • For voice production, the respiratory system provides the air flow needed to cause the vocal cords to vibrate and produce sound. This is the “power source” for our voice.

• Phonation (structures in the larynx, including the vocal cords):

  • The vocal cords are muscles positioned at the top of the airway (trachea), near the opening of the esophagus (the tube that carries food/liquid to the stomach). The primary function of the vocal cords is to close when we swallow, acting as a valve to prevent food and liquid from entering the airway. This function is life sustaining!

  • In voice production, the vocal cords are the “sound source”. Air flow supplied by the respiratory system, pushes between the vocal cords and causes them to vibrate, which produces a sound which we call our “voice”.

• Resonance (pharynx, oral cavity, nasal cavity, tongue):

  • The primary functions of these structures are to: 1) prepare food for swallowing by chewing and 2) move the prepared food into the esophagus via the constricting muscles in the throat. These functions are life sustaining! (are you seeing a pattern here?)

  • The vibrations from the “sound source” are “shaped” by the structures they travel through. There are LOTS of acoustic principles involved in this process, but the result is the unique sound quality that is our “voice”.

• Articulation (muscles of the tongue, soft palate, jaws, lips):

  • The primary function of these structures is to support chewing and swallowing. Again, life sustaining functions!

  • In vocal production, these structures permit precise shaping of the “sound source” to produce specific speech sounds; speech sounds that are understood by groups of people to represent a “thing” or an “idea”; speech sounds that are connected in a pattern that permits us to communicate with each other via what we call “speaking”.

What could possibly go wrong?

Disruption to any aspect of the “four systems” that contribute to vocal function can result in difficulty producing speech that is easily understood. Below are some examples of injuries and/or disease processes that can affect vocal function:

• Head & Neck Cancer - Surgery and radiation may injure neural pathways controlling muscles involved in any voice production, or may require removal of a structure that is involved in voice production. If, for example, control of vocal cord movement or movement of the “articulators” is affected, one might experience a “breathy” vocal quality or have difficulty pronouncing speech sounds clearly.

• Neurodegenerative diseases affecting muscle control - Diseases such as Parkinson’s Disease or Progressive Supranuclear Palsy often disrupt the body’s ability to control muscle movement or to provide accurate “feedback” as to speech loudness and/or speed. Since muscle control is vital for all aspects of voice production, it is common for respiration, phonation, resonance, and articulation to all be affected to some degree as the diseases progress.

• Stroke/Traumatic Brain Injury - Strokes and TBIs cause brain injuries that are specific to regions of the brain affected by the trauma or restricted blood supply. Injuries that occur in regions of the brain that facilitate muscle movement or coordinaton of movements for any aspect of the “four systems” may result in difficulty producing speech that is easily understood.

• Vocal “abuse” - Teachers, singers, actors and others who use their voice many hours each day, frequently speak loudly to be heard in group settings, or who speak or sing professionally, may experience problems of vocal overuse or excessive vocal strain, referred to as vocal “abuse”. Injury or strain on the vocal cords may result in changes in voice quality (e.g. a “hoarse” voice, breathy voice, abrupt and unintended pitch changes).

Contact our clinic today to learn more about services we offer to address voice concerns and to schedule a free consultation appointment.