Emily C.: DYV, Ch. 16

Discover Your Voice: Chapter 16

Emily Cottam

Chapter Summary: The vocal folds, according to Jackson and Jackson, have nine basic functions: respiratory, valvular (control affecting positive/negative pressure in lungs), fixative (stabilize thorax for arm movement), protective (prevents foreign things to enter lungs), diglutitory (no food/water enter lungs), tussive (cough to repels foreign bodies from larynx), expectorative (clearing throat), emotional (creative/reflexive sounds), phonatory (communication). The larynx has four basic structures: cricoid cartilage, arytenoid cartilages, thyroid cartilage, and the hyoid bone. (There is also the epiglottis, two connuculate and two cuneiform cartilages.) The intrinsic laryngeal muscles are as follows: TA muscles (vocal folds) with the epithelium (mucous lining). They shorten and thicken and can be stretched. The PCA separates the vocal folds. The LCA adduct the vocal folds, and in extreme action can carry entire arytenoids forward for whispers. The IA close the posterior opening between the arytenoids. The CT muscles have pars recta (draws thyroid and cricoid cartilages together) and pars obliqua (pulls on inferior horns of thyroid cartilage in a gliding motion). The CT, according to Brown, are the “singer’s muscles.” The extrinsic laryngeal muscles are: the sternohyoid muscles (lowers hyoid bone/stabilizes larynx in loud singing); sternothyroid muscles (draw larynx down on inspiration/stabilize larynx); omohyoid muscles (lower/draw back hyoid bone/larynx); thyrohyoid muscles (decreases distance between the thyroid cartilage/hyoid bone. It contributes to unnecessary tension); digastric (raises hyoid bone or lower the jaw; it can pull your larynx up); stylohyoid (draw hyoid bone up/back); geniohyoid (elevates hyoid bone/draw it forward); genioglossus (draw hyoid bone forward/protrude tongue, tongue tension); hyglossus (can cause tension in larynx positioning); mylohyoid (stiff jaw). 

Key Concepts: “Freedom of motion is key to free phonation.” Extrinsic muscles must be in a state of release for free singing. Each voice is unique, and the environments that we are raised in can also influence our sound. Understanding the different parts of the voice can help us to understand the limits and potential of our voice. The structures involved in singing is supremely complex, and because of this, we cannot make sound happen, but we must trust and let. 

Key Terms: Vocal fold functions, Larynx anatomy, intrinsic and extrinsic laryngeal muscles

Making Connections: First off, I’m proud of myself for knowing almost all of the structures he listed in this chapter, excluding the extrinsic laryngeal muscles. I have found that learning the anatomy of the voice has been helping me to understand what happens exactly during good singing.