Signal 1 of 6
Pitch
Pitch is how high or low your voice sounds, and nerves tend to push it up.
Why We Freeze, §2 · Laukka et al., 2008; Pisanski et al., 2018Illustrative
The Science
Your voice shows when you’re nervous.
Levay listens for six signals in how you speak, and compares them with your own normal. Here’s what each one is, and what the research says.
Signal 2 of 6
Jitter
Jitter is tiny wobbles in the timing of your voice, one of the “shakiness” signals nerves can stir up, though studies find it less consistently than pitch.
Why We Freeze, §2 · Giddens et al., 2013Illustrative
Signal 3 of 6
Shimmer
Shimmer is tiny wobbles in how loud each vibration of your voice is, another shakiness signal that also shows up less consistently than pitch.
Why We Freeze, §2 · Giddens et al., 2013Illustrative
Signal 4 of 6
Speech rate
Speech rate is how fast you talk, and nerves usually shift it, but whether you speed up or slow down varies a lot from person to person.
Why We Freeze, §2 · Kirchhübel et al., 2011Illustrative
Signal 5 of 6
Pauses
Pauses are the silent gaps between your words, and nervous speakers tend to leave more of them.
Why We Freeze, §2 · Laukka et al., 2008; Wörtwein et al., 2015Illustrative
Signal 6 of 6
Fillers
Fillers are the “um”s and “uh”s we say while hunting for a word, and nerves can make that hunt harder by using up the working memory you search with.
Why We Freeze, §3 · Eysenck & Calvo, 1992Cited for the working-memory effect. The paper doesn’t measure filler counts directly.Illustrative
What it looks like over time
Nerves that come down.
Practice a little every day and your nerve score drifts down, compared with your own starting point.
Example data
Everyone’s voice is different. Voice signals are noisy and each person’s voice reacts a little differently, so Levay compares you with your own normal, never with other people. One 2025 meta-analysis found the pitch effect shrank a lot once it corrected for publication bias (Veiga et al., 2025).
A practice tool, not a medical test. The charts on this page are illustrations, and the 30-day graph is example data, not a result from real users. “Why We Freeze” is a literature review, not an experiment.
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