Updated October 2026 · Part of singing technique.
Vocal distortion is noise added to a note on purpose: the rasp in a blues line, a rock growl, a metal scream. Done right, the noise is made above the vocal folds — by the false folds and the other soft tissue at the top of the larynx — while the true folds keep doing their normal job underneath. That is what makes it survivable night after night, and it is also the whole trick: the moment the true folds themselves are being squeezed to make the sound, you are no longer distorting, you are damaging. This page covers what distortion is, how it is produced without harm, the sounds and the styles, subharmonics, and an exercise to find a growl. It is also the one page on this blog where the honest advice is: get a teacher to watch you do it at least once.
What is vocal distortion?
A clean sung note is a tone: the vocal folds vibrate regularly and the vocal tract shapes the result into a vowel. Distortion adds irregular vibration on top — noise — and the more noise, the less tone. At one end of the scale is a light rasp that barely changes the pitch; at the other is a scream in which the note is almost gone and only the noise is left. Rasp, growl, grunt, squeal, “dirty” tone, fry scream and false-cord scream are all points on that scale. What they have in common is emotional: distortion reads as effort, pain, aggression or ecstasy, which is why it turns up wherever singing needs to sound like more than singing — gospel, blues, soul, rock, metal, Mongolian and Tuvan throat singing.
Two warnings belong up front. Distortion is an effect, used on some notes, not a way of singing; if you can no longer sing a clean note without it, you have trained the wrong thing. And distortion must never hurt. A scratchy, itchy, strained feeling is not the sound arriving; it is the true folds taking the load, and the session is over.
How is distortion produced safely?
Above the true vocal folds sit a second pair, the false or ventricular folds. They are mostly fatty tissue and mucous glands — their day job is to lubricate the true folds and protect them — and they do not normally vibrate. Squeeze the larynx the right way and they can be brought into the airstream, where they flap irregularly and produce a rattling, raspy sound. The aryepiglottic folds and the tissue at the top of the larynx can join in. When laryngologists have filmed metal singers screaming, this is what they see: the true folds still phonating, more or less cleanly, with the structures above them vibrating on top (Eckers et al., 2009). The noise is made upstairs; the delicate instrument downstairs is not being abused.
That is the safe version, and it has three conditions. The breath has to be fully supported, because distortion needs more airflow than a clean note and the throat must not supply the pressure — breath support comes first. The true folds have to stay as relaxed as they would be for a clean note at that pitch; the squeeze is above them, not in them. And volume comes last: because the effect lives above the folds you can add a lot of volume to it without harm, but only once the coordination is there. Change the volume, the pitch, the amount of air and the mouth shape and the same mechanism goes from a sexy growl to a deathcore scream, from grunting to throat singing.
The unsafe version is the one most people find first: pressing the true folds together hard, pushing air through them and getting a rasp out of the friction. It sounds similar for a week. It is also how nodules are made.
Which styles use distortion, and what are the sounds called?
Louis Armstrong’s rasp, Janis Joplin’s growl and Christina Aguilera’s grit are all distortion in a jazz, rock and pop setting: a dirty edge on a note that is still clearly a note. Throat singing (Mongolian and Tuvan, as in The Hu) uses the same structures for a sustained drone with the noise as the texture. Hard rock and metal have taken the effect furthest and have the most vocabulary for it. Mid screams keep the words over-pronounced; low screams mostly lose the lyric; the “high” and “low” in those names are about timbre, not pitch. The fry scream is quiet and uses very little air, which is why it can be held for a long time. False-cord screams are the loud, full-throated kind. Then there are pig squeals, low gutturals (mostly a tongue position), inhale screams, tunnel-throat screams, and whatever the next subgenre invents.
There has not been much research into whether every one of these is the same mechanism dialed differently or several mechanisms, and the voice experts who warn that distortion can damage the folds are right about the unsafe version. The practical position is the one Celina took in the first edition of this article: if distortion is the sound you want, don’t be afraid to try it — carefully, and listening to the body. Singers learn by imitating sounds they like. Where distortion sits next to the other power techniques is in contemporary vocal techniques: heavy modal, twang and belting; the clean, loud high note that distortion is usually added to is belting.
What are subharmonics?
Subharmonics are a related but different trick, and the question comes up often enough to answer here. When the true folds and the false folds vibrate together at a fixed ratio — the false folds at half the frequency, say — the ear hears a note an octave below the one the true folds are producing, sometimes with a buzzing, “two notes at once” quality. It is the mechanism behind the Tuvan kargyraa style and behind the viral clips of singers dropping below their natural range. To find it, start from a hum at a comfortable low pitch and slide downward until the tone starts to break up; at that point, keep the airflow steady and add a little friction above the folds — the same place the growl lives — and listen for the octave to drop in. It takes weeks of short attempts, not one session, and all the rules above apply: supported breath, no squeeze in the true folds, stop at the first scratch.
Can you learn distortion without a teacher?
Partly, and this is the technique where “partly” matters most. The problem is feedback: the safe growl and the harmful one sound alike from inside, and the damage from the harmful one arrives days later as hoarseness rather than as pain in the moment. A teacher who knows the technique can see and hear which structures are working within a few seconds, and that one check is worth more than a month of experiments. If you have no teacher, the online lessons guide covers how to find one for a single session. Meanwhile, the rules for working alone: never from a tired or hoarse voice; support in place before any noise; thirty seconds at a time with rest between; volume last; and water. The sore-throat post has the signs that mean stop for a day and the ones that mean see a doctor.
Do you have a raspy voice, a damaged voice, or a clear one?
Where you start depends on which of three voices you have. Some people have a natural rasp — it is anatomy, and it does not change; the thing to do is make it part of your style rather than fight it. Some have a rasp because the voice is damaged, by overuse, strain, smoking or drugs; that rasp is a symptom, not a technique, and the route to distortion runs through rest and, if it has lasted more than three weeks, a doctor. And most people have a clear voice and want to add grit. For them the first access is usually through the sounds the voice already makes in daily life that aren’t singing — a cleared throat, a cough, a theatrical whisper, a vocal-fry “uh” — which are exactly the things a vocal-health article tells you not to do. Distortion is where the singing rulebook gets suspended for a few minutes at a time; the price is that the few minutes have to be careful ones.
Exercise: how to growl
Celina’s growl exercise, on video and in steps:
- Warm up first — the usual ten minutes, so the true folds are already working easily.
- Sing a clean “ah” on a comfortable note in the lower middle of your range, at medium volume, with the breath supported and the throat open. This is the note the growl will sit on; if it isn’t easy, pick a lower one.
- Let the sound go slightly breathy, then add a vocal-fry edge — the creaky “uh” of a lazy morning voice — without changing the pitch. The fry tells you the folds are loose, not pressed.
- Now ask for the rattle from higher up: imagine clearing the throat gently while the note continues, or the sound of a cat’s purr placed in the throat rather than the chest. The tissue above the folds should start to flutter. If the note cuts out or the throat grips, you squeezed the wrong thing; go back to step 3.
- Hold it for a few seconds, stop, swallow, breathe. Three or four repetitions, then leave it for the day. Add volume only when the quiet version is reliable.
Questions to ask the moment anything hurts: Are you too loud? Is the breath actually supporting, or is the throat doing it? Have you had water? When did you last rest the voice?
Frequently asked questions
Is vocal distortion bad for your voice?
Not when the noise is made by the false folds and the structures above the true folds, with the breath supported and the true folds relaxed — professional metal singers scream for two hours a night for decades. It is bad when the rasp comes from pressing the true folds together and forcing air through them. The difference is invisible from inside, which is why one session with a teacher is the safest start.
What’s the difference between growling and screaming?
Degree, and pitch. A growl keeps a clear note under a heavy rasp, usually in the low or middle range. A scream pushes the balance toward noise and is often placed high; a fry scream is the quiet, long-held variant and a false-cord scream the loud one. Same tissue, different settings of volume, air and pitch.
Why does my throat hurt when I try to growl?
Because the true folds are doing the work. Either the breath isn’t supporting and the throat is supplying the pressure, or you are squeezing at fold level instead of above it, or both. Stop, rest, and go back to the clean note with fry — the rattle should be added to an easy note, never forced out of a tight one.
Can a clear voice learn to sing with rasp?
Yes; most distorted singers started with a clear voice. It is learned the way the growl exercise above learns it: a loose, fry-edged note first, then the rattle from above, then volume. Expect weeks of short attempts, and expect it to sound silly before it sounds dangerous.
Distortion is one coordination among several; the map of the others, and a five-minute self-check for which one is holding you back, is on the singing technique guide. To see what your clean voice can do before you add noise to it, take the vocal range test.
Sources
- Eckers, C., Hütz, D., Kob, M., Murphy, P., Houben, D., Lehnert, B., “Voice production in death metal singers”, NAG/DAGA International Conference on Acoustics, Rotterdam (2009).
- Sadolin, C., Complete Vocal Technique, Shout Publishing — the “distortion”, “rattle” and “growl” effects as separate, teachable sounds.
- Van Doorn, I., Singing from the Inside Out.
- National Institute on Deafness and Other Communication Disorders, Taking Care of Your Voice.