There are currently almost 7,000 languages spoken worldwide, with countless dialects, accents, and quirks to any individual’s speech. A DNA survey from 2002 revealed that all humans are genetically 99.9% identical. It amazes me that one species (Homo sapiens) can be so similar, yet possess so many variations of speech, which leads me to ask, why do we speak the way we do? How do we get our voices?
An article from Mental Floss claims that our voices are as unique as fingerprints- with no two being exactly the same. The National Center for Voice and Speech offers an “equation” for an individual’s voice: “Voice Quality = laryngeal anatomy + vocal tract configuration + learned component”. Let’s break this down so that myself along with other non-linguists can understand.
- Anatomy: The anatomical features that produce human voice are known as the vocal tract. This includes the lungs, the larynx (also known as the “voice box”), and the oral and nasal cavities. The lungs provide the airstream which
powers human voice. As air is pushed up the windpipe from the lungs, the larynx, which is made up of two vocal folds, opens and closes to produce vibrations. These vibrations are carried through to the throat, nose, and mouth, which act as resonators- morphing the vibrations into distinct human sounds.
2. Vocal Tract Configuration: The shape of any individual’s vocal tract is due partially to genetic makeup: you are born with a certain neck length, pharynx width, etc, all which affect the sound produced. However, you can also manipulate your vocal tract in order to produce a certain sound. Singers practice “vocal tract shaping” all the time so that they can create their desired voice. For example, pursing your lips into an “O” shape elongates the vocal tract, resulting in a deeper sound. Each small movement of any part of the vocal tract, intentional or not, will affect the sound that comes out of your mouth.
3. Learned Component: Part of our speech is learned traits or habits, formed by our environment. Things like “rhythm and rate of speech and vowel pronunciation”, according to NCVS, are unique to each individual, but can be similar within families or those who spend a lot of time together.We tend to unconsciously mimic the speech patterns of those around us, leading to different accents or dialects of the same language, such as the “southern” accent, Boston accent, New York accent, and many more sub-dialects. Individuals can also “learn” to speak differently over time spent in a new culture, or intentionally though speech therapy.
While these factors all contribute to the uniqueness of our individual voices, there are terms that can be used to describe recurring vocal characteristics. These include the hoarse voice that typically accompanies a sore throat, a flat or monotone sounding voice, a high-pitched penetrating voice, a gravelly or low and rough voice, among others. Pay attention to the way you speak; try changing the shape of your vocal tract to talk in a different accent and I’m sure you’ll be surprised with how you can manipulate your own voice. I tried to maintain a fake “southern accent” for just a few minutes and had to give up because of how difficult it was. Yet our bodies produce our own special dialects every single day without us even having to think about it! Just another way to be amazed by the workings of the human body.