Listen to an album that showcases harsh vocal techniques. Good bands include Deicide, Morbid Angel, Cannibal Corpse, Suffocation, Behemoth, Hate Eternal, Vader, Pestilence, Possessed, Disgorge (US), or Death.
Learn how to sing properly. Start with something with vibrato, like Classic Rock or Progressive, i.e. Nevermore. The most important technique for performing death metal vocals is to be able to control your breathing, establishing a balance between the force used by your diaphragm and vocal cords. Using only the vocal cords will put undue pressure on them and is sure to damage them (minor damage will heal in time). Proper technique is established by using the diaphragm to push air out of your lungs.
Warm up your voice before recording or performing death metal. "Warming up" can mean anything from singing mid-tone melodies to delivering your vocal patterns in a clean chest tone. Even humming for five minutes would be more beneficial to you than not warming up your voice at all.
When performing live, drink lukewarm water or tea an hour before performing, as well as in between songs. Avoid cold water, as it shocks the voice. Following these simple guidelines will help protect and strengthen your vocal chords. If you don't sing properly, you may not be singing for much longer.
Fill up your lungs with air, then push out some of the air, tightening your throat and moving your tonsils as you do this. Do this all in one motion, but don't push too hard. Aim the sound higher in your throat to make a "dying old man"-like sound. It should sound something like a black metal raspy voice. From there lower the pitch in your throat the same way you would with your normal voice. At first, it won’t sound like much-- it takes some time to get used to.
Pick a lyric you want to perform. Try to choose songs from bands like Slayer, Metallica, AC/DC or other bands who do not use the death grunts, as it will be easier to rehearse your grunts (Six Feet Under has redone classic rock songs and given them a Death Metal makeover). Try singing it normally, then slowly add more "fire" to it, until you can feel your diaphragm really pushing and you're getting that deep sound you're looking for. If you don't succeed in the deep guttural vocals try the raspier approach to these vocals like Mark Hunter of Chimaira. Anyone can achieve this, men as well as women (listen to the current vocalist for Arch Enemy), as long as their vocal range is Alto or lower. Arch Enemy's Vocalist Angela Gossow is an alto, and will say it herself--if you are a Soprano, don't even try Death Growls.
Practice barking like a dog. Take a deep breath and go from your diaphragm. Force the sound out from the bottom of your belly, really imitating the barking sound. Then extend the barking sound and try it with several words. Breathing like a dog, as stupid as it sounds, can help you open your throat and get a guttural sound to your grunts. Don't do it loudly at the beginning--increase your volume as you get better at it.
After you've mastered basic death grunts, move on to bigger things. Make your grunts louder, faster, lower, deeper, or all of the above. It will help add some variety to your vocals.
After you've mastered death metal vocals, try to mix things up by learning another vocal style--even the best death metal vocalists don't use only death grunts in their songs. For example, George Fisher of Cannibal Corpse is known for having high-pitched screams in a few of his songs and Trevor Strand of The Black Dahlia Murder has been known for using a mix of death grunts, high-pitched shrieking and screaming.Also Jerry Sturino from Path changes his pitch during his songs Also, start headbanging when you're performing the vocals. It will make your presentation seem a lot more intense!
After you're done performing death metal vocals, be sure to drink a healthful beverage such as the universal choice, water. Milk is also a good choice as it provides proteins and naturally produces phlegm, which will help to soothe and coat your throat. (Note that if your throat is sore, you're most likely doing something wrong.) Don't drink juice-- it contains citric acid, which will eat away at your throat.
Tips
The smooth muscles of your throat should not ever hurt while performing death metal or black metal vocals. However, when you first start out the exterior muscles of the throat will become sore from holding your throat in a new position.
The sound should be originating from the spot in your throat located at the center of your collar bone where it dips in a bit (Larynx/Voice Box/Adams Apple).
Be a badass and learn how to sing clean vocals as well. You'll be more useful in a band.
Constantly experiment with what your throat can do!
Learn to control rasp and phlegm. (Rasp is air coming up; phlegm is mucus in your mouth and throat)
Harsh vocals will grow in volume as you gain skill with them and use them correctly.
Don't use distortion or effects to cover any lack of vocal ability. It sounds bad and it's obvious why you did it.
To create a more "brutal" sound, you can experiment with saliva in your mouth. It can be trapped between your tongue and throat. It's that "gurgling" you hear in many songs. An open throat is the key. The notes sung and air must come up with ease. One can use their tongue to deflect air being forced up and change tone. The lips are the second method of changing tone. You should never change tone by tightening your throat. There are many techs used in harsh vocals, but keep with a simple growl and scream until you've gained quite the skill within this vocal type.
A little advice from George "Corpsegrinder" Fisher from Cannibal Corpse. When asked in an interview if his vocals strain his throat, he commented: "Not anymore. That's the funny thing. People ask me like, "Well, how'd you learn to sing like that?" Because I put on the albums and started singing to them. And some people say to me, "But my voice starts to hurt after ten minutes." Well yeah, but . Practice this until you can hear the gargling noise in the back of your throat.
A good way to practice your grunts is to say the letters a, e, i, o, n, u. As you get better at your grunts, try doing this faster.
The "cookie monster" effect must not be reproduced by straining your voice. That will only damage your vocal chords. You have to push through your abdomen. All of your vocal strength comes from the diaphragm. It also helps if your back is in a fixed position. Don't slouch or leave your spine limp. Inhale and belt out a deep roar by loosening your vocal chords. Your throat has to be relaxed in order for your growl to rumble with intensity. Again, don't force your voice to crack. If it still doesn't crack, then your vocal chords simply weren't made for pitch will be lower. This inhaling technique can produce an extreme range of pitch, allowing you to both grunt and squeal like a pig. The incoming airflow will be nowhere near the volume of normal speech. You will need to speak using exaggerated lip movements and the front of the tongue while keeping the back of the tongue muscle in place. While an "inhale vocal tech" may sound "cool", be careful using it. It can (and likely will) damage your vocal cords. The inhale sound can still be created from properly done harsh vocals but requires range needed.
Don't smoke, and if you insist on drinking, drink in moderation. Smoking may deepen your voice, but it will also reduce your breath support. Delivering death vocals requires a great deal of energy, and drugs of any sort will only emasculate your staying power.
Exercise is a good idea. You'll need strong neck muscles to support the pressure that extreme metal vocals put on your neck area.
Over time you'll learn your range, your skills will increase, and you can try to achieve your favorite sounds.
Practice normal singing for a month first. This will really strengthen your vocals cords and make it easier on you when you start doing death growls.
Be sure to have variation in your vocals. Monotone growling will sound boring after awhile, no matter how impressive your vocals are. A good vocalist for inspiration is Matthew Chalk, formerly of Psycroptic.
Drinking a lukewarm liquid may aid in expanding your vocal cords, helping your voice get deeper.
How your mouth is shaped will help define the tone of your voice. For example, if your mouth is opened like a fish mouth, a lower tone can be achieved. Also, cupping your hands around the microphone will not only make your voice louder, but can also help to deliver deeper growls.
If you're already good at screaming, picking up death metal vocals should be a piece of cake. Already having skill in death metal singing is also a benefit when learning.
With two vocalists, one doing high or violent shrieks and another doing deep in harmony can create a superb sound. Bands such as Deicide, Despised Icon, Carcass, Dying Fetus, Novembers Doom, Draconian, Exhumed and Nile use this in different ways to great affect.
Visualize a column of air rising from your diaphragm, through your chest, and up through your facial mask (the space behind the nose, under the eyes, above the upper teeth.) Keep your larynx down also. This technique will not only help your death metal vocals be strong and present, but is also the correct technique for melodic singing. The only difference between them is that regular voice comes from your vocal chords while death metal vocals come from your false vocal chords. (Instead of vibrating your vocal chords, focus your growling sound under your vocal chords, around your collarbone.)
“Timing’s a big deal. When someone’s out of time, anybody that hears it is going to know. It just sounds like mush. I’ve seen bands where I know when somebody is off. More so with the vocals and the drums, I can tell that as well because I’ve followed drums my whole life. For timing, it can be hard when you’re banging your head the whole time. We do have a lot of stuff that’s in 4/4, but it’s not simple. You’ve got to pay attention to what you’re doing. I’m still banging my head, but I’m counting the whole time, and then you’ve got people diving stuff going on around you the whole time. It is a challenge. I’m not saying it’s the hardest thing in the world to do, I just get annoyed when it’s made out to be easy, or at least what I’ve heard from people about this DVD."- George "Corpsegrinder" Fisher
GOOD PRACTICE SONGS:
SLOW:
Normal Vocals: “Black Sabbath” by Black Sabbath, “Dead Skin Mask” by Slayer, "Hard Rock Hallelujah" by Lordi.
Death Metal Vocals: “Death Walking Terror”- Cannibal Corpse, "Festering in the Crypt" by Cannibal Corpse, “I Cum Blood” by Cannibal Corpse, "The Jealous Sun" by Novembers Doom, "Sarcophagus" by Nile
FAST:
Normal: “Aggressive Perfector” by Slayer, “Dittohead” by Slayer, “Jesus Saves” by Slayer, “Necrophobic” by Slayer
Death Metal: “Disposal of the Body” by Cannibal Corpse, “Homage for Satan” by Deicide, “Post Mortal Ejaculation” by Cannibal Corpse, “The Exorcist” by Possessed, "The Optimist" by Skinless, "4:20" by Six Feet Under, "Stabwound" by Necrophagist, "Egypt, the Red Earth" by Necronomicon, "Buried By The Dead" by Bloodbath, "Sick Salvation" by Bloodbath, "Prometherion" by Behemoth, "Scrolls of the Megilloth" by Mortification, "Demon of the Fall" by Opeth.
Warnings
All singing of this type degrades your voice permanently, resulting in loss of range as well as other serious disorders such as vocal nodules and polyps (growths on the vocal cords). "Correct technique" can minimize this damage, but it is important not to overdo it and to protect your voice just as your band's guitarist would with his guitar (the expensive one, not the one he smashed at your last gig). Remember, a guitarist can always buy a new guitar, but you only get one chance with your voice. Try using a technique called "Marking" which is used by professional singers, from genres Metal to Classical, in which you only talk the shouting lyrics and then during recording/preformance you actually shout. It can help alot and is very useful!
Inhales are not a reliable technique for death metal. They often sound too high pitched and are more or less a way of cheating. Although they may not hurt your voice, they just don't sound as cool.
You can severely damage your voice if you use prolonged bad technique, although mild damage will heal in time. If your vocals do become damaged stop doing harsh vocals and whispering! Normal talking should be fine.
Don't smoke or drink excessively if you want to do these vocals! It may provide pain relief at the time, but you will pay for it later. It's hard enough to scream/growl and headbang without any toxins in your system.
Don't be surprised if you don't sound like your favorite harsh vocalist—everyone has a different singing voice.
Prepare for some raised eyebrows and harsh criticism when showing friends or family your unique style of singing. Some people don't consider death metal singing real singing at all.
There's a chance that these vocals might mess up your voice a bit and make you sound like you have the flu when you're not singing. This is what happened to George "Corpsegrinder" Fisher from Cannibal Corpse. But the chances aren't too high, because if you notice, many other harsh vocalists, like Chris Barnes, Glen Benton, Nergal and Angela Gossow all have normal talking voices.
If you go for the extremely low/brutal Chris Barnes-style vocals, the chance is greater that you will damage your voice.
If you have a throat infection , a cold or the flu with coughing, give your vocals a rest for a day or two.
Harsh vocals always come from your gut, never your throat.