You’ve probably seen a scene in a horror, sci-fi, or suspense movie where a character is suddenly frightened. All she needs to do to alert others to the danger or to save herself is to scream out for help. Yet she can’t seem to get her voice to work. The scream is stuck in her throat.

This type of scene usually frustrates me. Just scream!, I think. But Hollywood might be on to something. We know that when we feel stress, our body often reacts to that stress by fighting, fleeing, or freezing up. But how does that stress specifically affect our voice?

It turns out there’s a link between stress and vocal performance. Maria Dietrich, Richard D. Andreatta, Yang Jiang, and Joseph C. Stemple set out to prove that link. Their illuminating research was published in Brain Imaging and Behavior in May of 2019. The study is the first to provide scientific evidence that the stress of preparing to give a speech directly affects our normal ability to produce sound and control our voice. Let’s explore a few of the key findings from this groundbreaking research.

How the Study was Conducted

The researchers recruited 13 participants who were told they had to give a five-minute impromptu speech in the next few moments. The participants were studied via fMRI imaging and saliva samples while they prepared for their speech.

During the speech preparation, the team noted a spike in the stress hormone cortisol. While those stress hormones spiked, other areas of the brain showed a decrease in activity. Those areas of the brain, interestingly, are directly connected to vocal control.

What Showed up in Brain Activity

We know that stress has a profound effect on the human brain. But this study proves that it directly affects the regions of our brain responsible for producing phonation. “Phonation is the production of sound from oscillation of the vocal folds (or ‘vocal cords’) and resonance of the vocal tract, both of which are essential for normal speech.” In other words, it’s how humans make vocal sound.

The study found that stress reduced the activity in brain regions responsible for vocal control: specifically, the ACC, MCC, insula, putamen, and thalamus. When the activity in these regions is suppressed by stress, it’s harder to make and control vocal sound. This can lead to a feeling of tightness, dryness, or even immobility of your vocal folds. So if “the cat got your tongue” or you have “frog in your throat,” it could simply be the natural response of your voice to stress.

The Surprising Effect on Introverts

One interesting finding involved the difference in how the voices of introverts and extroverts were affected. Those participants who were extroverts were less affected by the spike in stress hormones. Those who were introverts, on the other hand, experienced greater stress and therefore, greater loss of vocal control.

The study “revealed ties between people who classified as introverts, high levels of ‘cortisol reactivity,’ and an additional decrease in activity in one area of the laryngeal motor cortex — a primary area of the brain that controls vocalization.” It was quite literally harder for introverts to speak up.

These findings help us to understand what is happening in our minds and bodies when we get up to speak and suddenly feel a lack of vocal control. Luckily, knowing what is happening can also help us to minimize the effects of the stress and to regain control of our voice.

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