What does a rise of "five semitones" actually mean?

By Nick Peplow·Founder and editor

Last reviewed 27 September 2026· How this site is researched

At some point in a voice surgery consultation, somebody shows you a number. It might be on a slide, in a paper, or on the surgeon's website: an average rise of so many semitones, or a speaking pitch that went from one figure in hertz to another. It is presented as the result, and it is hard to know what to do with it.

Reading it well means knowing what the units are, what a given rise sounds like, and what the number leaves out, which is most of what you care about.

Two units for one thing

Hertz (Hz) count vibrations per second. Your vocal folds open and close a certain number of times each second while you speak, and that rate, the fundamental frequency, is what you hear as pitch. Speaking voices typically sit somewhere between roughly 85 and 255 Hz, with a lot of overlap between men and women in the middle.

Semitones are musical steps: the gap between two neighbouring keys on a piano. Twelve of them make an octave, and an octave is a doubling of frequency.

The reason both exist is that the ear does not hear hertz evenly. A rise from 100 to 120 Hz sounds noticeably bigger than a rise from 200 to 220 Hz, although both are 20 Hz. The ear hears ratios. A semitone is always the same ratio, about 6 per cent, so a semitone sounds like the same size of step wherever it happens. That makes it the fairer unit for comparing results between people who started at different pitches.

What a rise sounds like

Two familiar tunes give a feel for size. The first two different notes of "Twinkle, Twinkle, Little Star" are seven semitones apart. The first two notes of "Here Comes the Bride" are five apart. A rise of two semitones is the gap between neighbouring notes of a plain major scale, "do" to "re".

In hertz, starting from a speaking pitch of about 110 Hz, those rises land roughly here:

• 2 semitones: about 123 Hz
• 5 semitones: about 147 Hz
• 7 semitones: about 165 Hz

Starting from 130 Hz, the same rises land at about 146, 174 and 195 Hz. Same number of semitones, bigger jump in hertz, because the starting point was higher. This is why a result quoted only in hertz can mislead: a 30 Hz rise means more for a low voice than for a higher one.

These are arithmetic, not predictions. They tell you what a reported number would mean for a voice at that starting point. They tell you nothing about what an operation will do for you, which depends on your anatomy, the technique, the surgeon, and how the healing goes.

Why the same voice gives different numbers

Pitch is not one number. It moves constantly within a sentence, so every quoted figure is an average of something, and what it is an average of matters.

A sustained vowel, holding "aah" for a few seconds, is easy to measure and tends to give a tidy figure. A reading passage is closer to real speech. Spontaneous conversation is the most honest and the hardest to standardise, and it is where tiredness and habit pull the voice down. A result measured on a held vowel can look better than the same voice sounds in a café.

Timing matters too. Pitch after vocal fold surgery settles over months, and some operations, cricothyroid approximation in particular, have a reputation for losing part of their rise over the first year or so. A number measured early may not be the number you live with.

Then there is the average itself. A mean rise across a surgeon's patients hides the spread. Some people will have gained more and some much less. Your result is one point in that spread, not the middle of it by right.

What the number leaves out

Everything else a listener hears. A rise in semitones is a rise in pitch and nothing more. It says nothing about resonance, intonation or vocal weight, which carry at least as much of how a voice is read. I have seen people with modest rises on paper who sound entirely like themselves, because their training was already strong, and people with larger rises who are still misgendered on the phone, because nothing else moved. The post on why pitch is not enough goes into that.

It also rarely says what was lost. Range, power, the top of the voice and singing are the usual costs of pitch-raising surgery, and they are harder to put a figure on.

Measuring your own voice the same way

A surgeon's before-and-after figure is only useful to you if you know your own starting point measured the same way. You can get close for free. Pitch-tracking apps on a phone will give you a running figure, and Praat, the free program many voice researchers use, will give you an average over a recording if you are willing to spend an evening learning it.

Whatever you use, keep the method fixed. Same passage, same time of day, same distance from the microphone, and a conversational sample as well as a reading. Record at the end of a long day too, because that is the voice surgery is meant to help with. A set of measurements taken the same way over a few months is worth more in a consultation than any single number, and it lets you check a surgeon's typical result against where you actually start.

One caution. Apps disagree with each other, and some jump an octave when a voice is breathy or creaky. Treat the numbers as a trend, not a verdict, and listen to the recordings as well as reading the figures.

Questions worth asking about any number

• Is that in semitones or hertz, and what was the average starting pitch?
• Measured how: a held vowel, a reading passage, or conversation?
• Measured when after surgery, and is there a figure at a year or later?
• What is the spread? How many people gained very little?
• What happened to the pitch floor and to the top of the range?
• What typically happens to volume and singing?

A surgeon who can answer those plainly, with their own numbers rather than someone else's paper, is telling you something good about how they work. If the answers are vague, treat the headline figure as a brochure, not a result.

This is general information, not medical advice. For the procedures themselves, see feminization surgery, and if you are at the beginning, start here.