Fundamental frequency

Fundamental frequency, written F0, is how many times per second the vocal folds open and close, measured in hertz (Hz). It is the physical quantity behind what listeners hear as pitch.

Where you'll meet it

In surgeon results ("average F0 rose from X to Y Hz"), in pitch-tracking apps, and in training targets. When someone quotes your speaking pitch as a number, this is the number.

What the numbers look like

Adult speaking voices are often described in rough bands: many men speak somewhere around 85 to 180 Hz, many women somewhere around 165 to 255 Hz. Those are loose, commonly quoted ranges, not clinical cut-offs, and they overlap. The overlap is the interesting part. A voice sitting in it can be heard either way, and what tips it is everything else: resonance, intonation, vocal weight and speech habits.

Nobody speaks at one frequency. Your F0 moves constantly within a sentence, so a quoted figure is usually an average over a reading passage or a stretch of conversation. Two measurements of the same voice on different days, or reading different passages, will not match exactly.

How it is measured

In a voice clinic, you read a standard passage, talk for a minute and sustain a vowel into a microphone, and software tracks the frequency and averages it. Many clinics also record your range, from the lowest note you can make (your pitch floor) to the highest. A phone app does a rougher version of the same thing.

The rougher version is still useful, as long as you compare like with like. Same app, same passage, same time of day. A voice first thing in the morning sits lower than the same voice in mid-afternoon, and a reading voice often sits higher than a chatting one. Recording yourself once a week under the same conditions tells you far more than checking the number every time you speak.

Hz versus semitones

Hertz are not evenly spaced to the ear. A 20 Hz rise near the bottom of a voice sounds bigger than the same 20 Hz near the top. That is why surgeons and therapists often report changes in semitones too, which track what you actually hear. The blog post on semitones works through what that looks like in practice.

What people get wrong about it

The common mistake is treating one number as the goal. I have watched people train hard to hit a figure on an app, get there, and still be read the way they were before, because the resonance and weight had not moved. The reverse happens too: a voice with a fairly modest average that nobody misreads.

The other mistake is reading a surgeon's average rise as a promise. It is an average across their patients, measured at a particular point after surgery. Yours may land above or below it, and the rise tends to settle down a little over the first months.

What changes it

Testosterone lowers it by thickening the vocal folds; the testosterone page covers how far and how fast. Oestrogen does not raise it. Surgery can raise it by shortening or tightening the folds, and training can raise the pitch you habitually use within the range you already have.

That split shapes the decision. If your trained pitch is where you want it but falls away when you are tired, the question is your floor, which is what surgery tends to move. If you have not trained yet, the number you would bring to a surgeon is not yet your real starting point.

← Back to the Glossary