How We Measure

The instrument itself, one parameter at a time: what the microphone hears, how each number is computed, and the part usually left out: what that number does not mean.

1. How Exprea Scores a Speaker

   Five axes, four sources that disagree with each other, and a sixty-day half-life. The complete method behind a Speaker Signature, including why pace, the thing we measure most precisely, is deliberately not one of the five.

2. What is speaking rate?

   Words per minute is the most quoted number in public speaking and the most carelessly defined. This article sets out exactly how we compute it, why our figure runs lower than most, and what the research supports.

3. What is filler rate?

   The percentage of your words that were "um", "like", or "you know". We count it two different ways in two different places. This article explains both, and why the number you see is an upper bound.

4. What is a pause?

   We define a pause as any silence between two words longer than half a second. That threshold is a choice, it is arbitrary at the edges, and it cannot tell a rhetorical pause from a speaker losing their place.

5. What is pitch variation?

   How far your voice moves in hertz over a clip, and the ratio that decides whether we call you monotone. Measured in your browser by autocorrelation, four times a second, with all the caveats that implies.

6. What is vocal energy?

   A normalised loudness figure from your microphone, and the one parameter we measure that is not comparable between two people, or even between two of your own recordings on different machines.

7. What is hedging rate?

   The share of your words that softened a claim before you finished making it: "I think", "maybe", "kind of". It costs half what filler costs, and four phrases are charged twice.