During rehearsals for the SATB choir I'm part of, we are sometimes asked to hum the melody of a song, or even scales as a warm-up exercise.

The humming-technique is sometimes explained as "keeping the mouth fully closed, but relaxed", producing what I would call the 'humming sound': 'mmmm'. This is confirmed by the remark: "when your lips vibrate, you're doing it right".

I notice that many people in my group and even the conductor are actually 'singing', producing an 'oo' sound (like in 'zoo') or 'oo' (like in 'none')*. This is done with a slightly open mouth.

My assumption is that it's hard to make herself heard over a group of 40+ in a large hall when ourconductor is explaining the exercise using strict humming. For the other singers I'm not sure why they would do that.

This led me to the question: "What sound should humming make?".

*I don't know the phonetic signs to indicate this, feel free to edit!

  • If the mouth is involved at all in the sound production, even to provide resonance, then it's not humming.
    – PiedPiper
    Oct 7, 2019 at 16:04
  • 1
    Press the small outer portion of your ear inwards, you can hear your humming quite clearly.
    – CrossRoads
    Oct 7, 2019 at 18:33

2 Answers 2


"Hmmm" with closed mouth indeed is singing through the nose: The tone of course produced by vocal chords in your throat but it should not come out through your mouth: so it will not sound different from a "nnnnnn"

(Humming is evoking and developing your spaces of resonance. You can feel this by the vibration of your cheeks, your nose and your breast and in the head (cranial). If everyone sings with more resonance the whole choir will have a greater sound and a bigger volume.)

Resonance refers to the amplification, richness and quality of your voice. Metaphorically, think of your mouth and throat as the speakers of your stereo system.

Ich bemerke, dass viele Leute in meiner Gruppe und sogar der Dirigent tatsächlich "singen" und einen "oo" -Sound (wie in "Zoo") oder "oo" (wie in "keiner") produzieren. Dies geschieht mit leicht geöffnetem Mund.

Try to sing "hm" with closed lips and add a vowel without opening your mouth, try to modulate the vowel from aouei you won't hear any vowels and also any difference at all.

  • 1
    My question is specifically about the produced sound. Should I read your answer as 'the sound is irrelevant, it's all about the resonance'?
    – MeanGreen
    Oct 21, 2019 at 14:29
  • Actually yes! I've edited my answer above. The sound will be not ohh or uhh at all, if they do what is asked. May be the conductor adds a vowel to be heard, but the choir should only humm. Oct 21, 2019 at 15:01

"What sound should..." is the main driver of vocal technique in my opinion, based on my limited experience in classical voice training. I'm always surprised when my voice coach teaches me how to shape my mouth and hold my jaw to make a simple sound that I thought I knew how to make.

There are possibly two things being combined in your question. Since you mentioned that this is a warm up, should it really matter if it's audible in an auditorium? As Albrecht said this is about exercising the resonance cavities in your head. In my experience the lip trill is really the exercise for this. But people do "hum" when they sing. There are pieces of music that direct one to hum.

Regardless of the word being pronounced or the specific sound being made by the vocalist, if it is part of the performance it needs to be projected and for that to work right you do not want to cover the sound, covering means obstructing it. This leads one to develop some unorthodox mouth shapes when pronouncing certain vowels and consonants as we try to keep the mouth open enough to push sound out and keep the cheeks raised to get resonance on the upper palate. A true "hum" will have a closed mouth but the shape of the jaw and cheeks is usually the same or similar to what you would make when singing with an open mouth.

I would guess that your conductor and some of the other performers are more experienced at these techniques and are able to hum with more volume.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.