In the mid-16th century, a unique phenomenon captivated Italy: male singers with an extraordinary vocal range that seemed impossible for adult men. These singers, known as castrati, possessed light, angelic voices that resonated throughout Europe. However, this remarkable gift came at a significant cost. To preserve their high-pitched voices, these singers underwent castration before puberty, halting the hormonal changes that would deepen their voices. This practice continued until it was outlawed in the 1800s.
While the castrati’s voices were artificially preserved, naturally developing voices are capable of a wide range of sounds. As we age, our bodies undergo significant changes that affect our vocal range. But how exactly does our voice box function, and what causes these shifts in speech?
The unique sound of a speaking voice is influenced by various anatomical factors, primarily the age and health of our vocal cords and the size of our larynx. The larynx, a complex system of muscle and cartilage, supports and moves the vocal cords, or more accurately, the vocal folds. These folds, positioned between the thyroid and arytenoid cartilages, form an elastic curtain that opens and closes across the trachea, the tube that carries air through the throat.
When we breathe, the vocal folds are apart, but they slam shut when we speak. Our lungs push air against these closed folds, causing them to vibrate and produce sound. Unlike playing an external instrument, we effortlessly change notes as we speak. By adjusting the speed of the air we push through, we alter the frequency and amplitude of these vibrations, which correspond to the pitch and volume of our voices. Rapid, small vibrations create high-pitched, quiet tones, while slow, large vibrations produce deep, resonant sounds.
By moving the laryngeal muscles between the cartilages, we can stretch and contract the folds, allowing us to intuitively play our internal instrument. This process remains consistent from our first words to our last, but as we age, our larynx ages too.
The first major shift in our voice occurs during puberty when the larynx grows, elongating the vocal folds and creating more room for them to vibrate. These longer folds result in slower, larger vibrations, leading to a lower baseline pitch. This growth is particularly pronounced in males, where high testosterone levels cause voice cracks and eventually deeper, more resonant voices, along with the development of laryngeal protrusions known as Adam’s apples.
Another significant change during puberty is the specialization of the tissue covering the folds into three distinct functional layers: a central muscle, a layer of stiff collagen wrapped in stretchy elastin fibers, and an outer layer of mucus membrane. These layers add nuance and depth to the voice, giving it a distinct timbre that differentiates it from pre-pubescent tones.
After puberty, most people’s voices remain relatively stable for about 50 years. However, as we age, we experience symptoms associated with aging larynxes, known as presbyphonia. The collagen in our folds stiffens, and the surrounding elastin fibers atrophy and decay, increasing the pitch of older voices. For those who have experienced menopause, the higher pitch is countered by swollen vocal folds, which slow their vibrations and result in deeper voices.
These changes are further complicated by a reduction in healthy laryngeal nerve endings, which diminishes precise muscle control and can lead to breathy or rough voices. Despite these challenges, when maintained in good condition, the voice box remains a finely tuned instrument capable of operatic arias, moody monologues, and stirring speeches.
Create a 3D model of the human voice box using materials like clay, cardboard, or 3D printing. Label the different parts such as the larynx, vocal folds, thyroid cartilage, and arytenoid cartilages. This hands-on activity will help you visualize and understand the mechanics of how we produce sound.
Conduct an experiment to measure your vocal range. Use a piano or a digital tuner app to find the highest and lowest notes you can sing. Record your findings and compare them with your classmates. Discuss how factors like age, gender, and health might influence vocal range.
Participate in a role-play activity where you reenact a historical debate about the practice of castration for preserving the voices of castrati. Research the perspectives of different stakeholders from the 16th to 18th centuries, such as musicians, church officials, and medical professionals. This will help you understand the ethical and cultural dimensions of historical practices.
Use a voice modulation app to simulate how your voice might change as you age. Record a short speech or reading at your current age, then use the app to adjust the pitch and timbre to reflect an older voice. Share your recordings with the class and discuss the physiological changes that cause these differences.
Interview a professional singer, speech therapist, or vocal coach about how they maintain their vocal health and adapt to changes over time. Prepare a list of questions based on what you have learned about the mechanics and aging of the voice. Present your findings to the class to gain insights into real-world applications of vocal science.
Voice – The sound produced by humans using the vocal cords, especially in speaking, singing, or other forms of communication. – The choir teacher emphasized the importance of warming up the voice before singing to prevent strain.
Larynx – A part of the respiratory tract containing the vocal cords, responsible for producing sound. – During biology class, we learned that the larynx is crucial for protecting the trachea and producing sound.
Vocal – Relating to the voice or the ability to produce sound with the voice. – The vocal performance of the lead singer captivated the audience with its range and emotion.
Folds – Refers to the vocal folds, also known as vocal cords, which vibrate to produce sound. – The doctor explained that inflammation of the vocal folds can lead to hoarseness and difficulty speaking.
Puberty – The period during which adolescents reach sexual maturity and experience changes in their voice and body. – During puberty, many teenagers notice a change in their voice as their vocal cords grow and thicken.
Sound – A form of energy that is produced by vibrating objects and travels through a medium such as air. – In physics class, we explored how sound waves are created and how they travel through different materials.
Vibrations – Rapid motions back and forth or up and down, which are responsible for producing sound. – The vibrations of the guitar strings create sound waves that are amplified by the body of the instrument.
Pitch – The quality of a sound determined by the frequency of the vibrations, perceived as how high or low a note sounds. – The music teacher helped students understand how to control their pitch while singing to stay in tune.
Aging – The process of becoming older, which can affect the voice by changing its tone and strength. – As a person experiences aging, their voice may become deeper or more raspy due to changes in the vocal cords.
Castrati – Male singers who were castrated before puberty to preserve their high-pitched vocal range. – In music history, we studied the role of castrati in opera and how their unique voices were highly valued in the 17th and 18th centuries.
