What if tomorrow you woke up and decided that you were going to stop speaking? Not for a day, not for a week — but for, say, 20 years. What effect would if have on your body? What effect would if have on your mind? Top photo by SarahElizabethC. via flickr
Before we begin, it's important to clarify that we're talking about the effects of long-term, self-imposed silence. The deliberate cessation of speech is fundamentally different from pathological conditions that affect our ability to talk, like dysarthria, dysphonia and aphonia. These are disorders that can be attributed to brain injury, neurological malfunction and/or the impairment of muscles that help produce speech. We'll reference these conditions later on.
But for the purposes of our discussion, we assume an otherwise healthy person who, for whatever reason, has chosen to stop talking.
Make Some Noise (Or Don't)
Phonation, or the production of speech, relies on the complex coordination of several anatomical features, but it's helpful to think of it as a sequence-dependent process that starts in your brain, proceeds through your voice box and ends in the resonating cavities of your throat, mouth and nose. Tinker with any part of the sequence and you'll hear changes at the end of the line. Singer Barbra Streisand (who is famous not only for her impressive vocal abilities, but her large nose), when asked what she thought it was that made her sound so unique, once attributed her voice to the sound-modulating qualities of her deviated septum. "If I ever had my nose fixed," she told her interviewer, "it would ruin my career."
Even more important than her nose, however, are Streisand's vocal cords. Also known as vocal folds, these two bands of smooth muscle are positioned opposite one another in your larynx, or voice box. When you decide to speak, your brain signals for these vocal folds to snap together as air from the lungs is forced between them by your diaphragm, a sheet of muscle positioned below your lungs. This causes your folds to vibrate. If you've never seen it before, this vibration makes for pretty excellent viewing material:
These vibrations produce sound that is modulated by the resonating cavities of your throat, nose and mouth before finally leaving your body. The pitch, volume and tone of your voice is determined by the strength, size and shape of your vocal cords, the force with which air is issued through them, and the shape of your resonating cavities.
Streisand owes much of her success to the control she wields over the muscles required for phonation (of which there are many, including the vocal cords and diaphragm, which we already mentioned, but also the muscles of the throat, lips, tongue, palate and jaw, to list a handful) — control that she owes, in large part, to years and years of vocal exercise. Singers train the muscles required for phonation the way a power lifter trains the muscles needed to perform a deadlift. If intense use and exercise can augment the strength, size, shape and command of one's vocal musculature, it stands to reason that intense dis-use of those muscles would have the opposite effect. If you woke up tomorrow and decided not to speak for the next 20 years, only to resume speaking later in life, it stands to reason you'd see some differences.
Your Multifunctional Vocal Muscles
We couldn't track down any studies that have examined the long-term physiological effects of voluntary speech-cessation, so we spoke to some experts instead. And while none of them were able to refer us to peer-reviewed research, they were kind enough to oblige us and speculate on the matter.
When we asked Katie Plattner, a speech language pathologist for the Los Angeles Unified School District, what would happen to your voice if you stopped speaking voluntarily, her answer was clear: "Probably not much."
The reason, she says, has to do with the fact that most of the muscles we use to speak get used all the time for things other than talking. We need our diaphragms to breathe, and the muscles we use to open and close our vocal cords are involved in everything from coughing, to clearing one's voice, to swallowing, to — get this — forcing out a stubborn poop. "You might have some trouble with vocal control," she explains, "just because you'd be out of practice, but your vocal folds would probably still be in fine shape. It's not like they'd completely atrophy or anything."
Plattner's informed opinion is supported by stories like that of Terry Wallis, who, in 2003, awoke from a 19-year coma (during which time he did not speak), and managed to utter "Mum. Pepsi. Milk." If Wallis' vocal cords had been weakened by his 19-year bout of silence, they were still strong enough to ask for a refreshment.
Voice recovery has also been observed in patients with psychogenic aphonia (a poorly understood form of pathological voicelessness that usually occurs in patients with underlying psychological problems), even in people who could not speak for several years. One woman regained her voice during yoga, while another got it back the day before she would have lost her job. "For patients exhibiting the symptom of voicelessness," write the authors of this study, "not eliciting the voice immediately will not lead to a permanent aphonia."
"Assuming otherwise normal physiology, I'd say that the only effect would be possible dis-coordination, or maybe vocal fatigue when you start talking again," says Plattner. She continues:
And by dis-coordination, I mean almost like when you ride a bike for the first time in years — you're kinda wobbly, but you can do it, and you get into it way faster than you would if learning for the first time... there's a lot of really precise timing involved in phonation for speech, so it might come out a little funny at first.
As for vocal fatigue (your larynx feeling sore or tired after talking), Plattner says that might be the bigger issue. One benefit of daily vocal exercise is a developed resistance to stress placed on the tissues of the voice box during prolonged bouts of singing or talking. Even if swallowing, coughing and pooping keeps your voice muscles from atrophying, it's possible that limiting the utilization of these muscles might make them more susceptible to fatigue. Underutilised vocal muscles might also affect your range of pitch, which is something that can be trained through talking (and even more so through singing). "Just plain phonation would be fine," says Plattner, "but without talking, you wouldn't really use the muscles that stretch vocal folds to change pitch."
But what about neurological changes — is there reason to believe that choosing not to speak could lead to adaptation in the brain?
According to Bijan Pesaran, an associate professor in NYU's Center for Neural Science and an expert on the brain's role in speech — there is. "Musicians with expert skills have enlarged [neural] representations for development processing, the same way athletes tend to have enlarged representations for spatial cognition." Our ability to speak, and speak well, says Pesaran, is not unlike a well-developed skill. Using those parts of the brain dedicated to speech will make them stronger. Underusing them will make them weaker.
If you are unable to use a bodily function, or choose not to use it, says Pesaran, you're liable to experience shrinking of the areas of the brain associated with it. This is different from the sort of "brain shrinkage" that comes with, say, old age. What Pesaran is referring to are the number of neurons that are available for and dedicated to the performance of a specific task.
"If you stop speaking, the number of neurons that are active, or could be active, for that process will get smaller, and the neurons that were once active for speech will become co-opted to do other things." The most striking examples of this kind of neural reorganisation occur when input of the function in question is cut off entirely. If you lose a finger, for example, the neural representations of the neighbouring fingers get bigger. Sever someone's optic nerve, and the neurons devoted to vision will be co-opted by neurons associated with other cognitive functions. "This is one reason blind people tend to have really excellent audio acuity," says Pesaran.
But at the same time, it's reasonable to assume that the neural reorganisation experienced by someone who chooses not to speak would be less dramatic than someone who — whether due to brain injury or nerve damage — is unable to speak. What's more, says Pesaran, speech is about more than talking. "Even if you stop speaking, you're not going to stop listening," he explains. The regions that handle motor control, and the ones that facilitate the production of speech, will probably shrink, "but the ones devoted to perception probably won't change much if the person leads an otherwise normal social life." That listening and speaking are all part of an integrated system could very well slow the rate at which neurons devoted to speech become co-opted by other cognitive processes.
Additional Reporting by Joseph Bennington-Castro