Can you make your voice deeper permanently?

What sets the depth of a voice

Pitch is how fast your vocal folds vibrate. Longer, heavier folds vibrate more slowly, so they sound lower. At puberty, testosterone makes male vocal folds grow longer and thicker, which is why boys' voices drop by about an octave. That growth carries on until about 18, so a teenager's voice often keeps deepening for years after it first “breaks”.

Hormones are the only thing that changes the folds themselves. That's why testosterone deepens trans men's voices. It's a medical treatment with real effects elsewhere in the body, and not a do-it-yourself project. Over-the-counter “testosterone boosters” have no good evidence of changing a voice.

What you can change, and keep

Within the range you have, you choose where to speak, mostly without noticing. Practice moves that choice towards the relaxed low end and adds a fuller chest resonance. Once it's automatic, it stays: that's the part that becomes permanent. Studies of voice training report speaking pitch dropping by one to three semitones. It's modest, but people hear it, especially with the fuller sound that comes with it.

It takes weeks of daily practice before the lower pitch is your default rather than something you remember to do.

Making your voice deeper permanently as a man

If you're an adult man, your vocal folds have finished growing, so the permanent part is habit: speaking from the relaxed low end of your range and with a fuller resonance until it's automatic. If you're a teenager, your voice is probably still deepening on its own until about 18. Practise good habits, but don't strain to force it lower; the growth will do more than any exercise.

Myths that “work” by damaging your voice

• Smoking.Long-term smokers' voices often do get lower, because smoke makes the vocal folds swell, a condition called Reinke's edema. It's damage, it sounds hoarse rather than deep, and it's the least of smoking's problems.
• Whiskey and late nights. Dehydration and irritation give a temporary rasp that goes away when you recover.
• Screaming or shouting to “break” the voice. This can cause nodules and lasting hoarseness. It never makes a voice deeper in a good way.
• Talking in vocal fry all day. The creak at the bottom of your range isn't depth, and it tires the voice.

When to see a professional

If you're past about 17 and your voice never dropped, or it keeps flipping up into a high voice, see an ENT doctor or a speech-language pathologist. Sometimes the voice stays high out of habit after puberty, a condition called puberphonia, and voice therapy usually helps it a lot. See someone too if you're hoarse for more than two weeks or speaking hurts.

The honest plan

1. Measure your speaking pitch with the free test, at the same time of day each time.
2. Practise the deep voice exercises for five to ten minutes a day.
3. Re-test weekly. If it moves a semitone or two and the voice feels relaxed, that's success.