Have you ever wonder why our voice sounds this way? The Speech Therapy Department at Singapore General Hospital shares some interesting facts on how our voice actually works.
Here are 10 little known facts about voice
- Prior to the Renaissance period, the voice was thought to be 'sent forth by the heart'.
- 'Vocal cords' are now more accurately known as 'vocal folds', to reflect the different layers of muscle, ligament and membrane that make up their structure.
- Normal anatomy of the human body includes both 'false' vocal folds and 'true' vocal folds.
- Many of the muscles used for swallowing are also used for talking.
- Fluids we drink for hydrating the body do not coat and lubricate the vocal folds directly. If that were to happen, we would choke and cough badly!
- Whispering may actually make your vocal folds work harder than simply talking softly.
- Maximum phonation time (MPT) is the average time during which an individual can sustain a sound (with one breath) at a comfortable pitch and loudness. An MPT of more than 15 seconds is commonly considered to be normal for adults.
- Women are thought to be more talkative than men, but males have been found to have a longer MPT than females in some studies.
- Voice problems usually have multiple causes. Even with good voicing technique that optimises breathing, vocal fold vibration and amplification, it is still possible to develop a voice problem if other lifestyle and medical issues are not addressed.
- In Singapore, voice therapy is provided by speech therapists, and specialised clinics to assess the voice are available in restructured hospitals like Singapore General Hospital (SGH), a member of the SingHealth group.
Piercing the mystery of voice
Voice is an instinctive process that most people use every day. Like a radio, anyone can "turn it on" anytime, anywhere, but few know how it works.
To pierce the mystery of voice, one needs to understand its three main subsystems: the power source, the vibratory source, and amplification.
The power source
- Breathing is essential for voicing. With each breath, the diaphragm muscles that separate the lungs from the stomach expand downwards. This allows the individual to take in as much air as needed to power the voice for speaking. During speech, air travels from the lungs to the windpipe (trachea) before reaching the voice box (larynx) at the top of the windpipe.
The vibratory source
- When exhaled air from the lungs reaches the voice box, vibration of the vocal folds produces sound. The pair of vocal folds is in a 'V' shape during quiet breathing. During voicing, the left and right vocal folds come together and oscillate in an opening and closing movement, producing a tiny "buzzing" sound. The sound produced is then carried by the air molecules upwards along the throat.
- Sound gets amplified and becomes audible through the various spaces in the throat, mouth and even nose. Typically, sound amplification through the mouth and nose is regarded as the most efficient. Additionally, the lips, tongue and teeth help shape sounds, enabling us to pronounce the various words used in speech.