Many years ago I had a singing teacher who tried to teach me the "stanley method" of lowering the tongue hard in the mouth - even practicing with a tongue depressor/icecream stick or spoon pushing the tongue down in the mouth.

I took his advice, dedicated myself to this approach - and strained the hell outta my voice.

It's surprisingly common to see even big name coaches and methods instructing to drop the tongue as much as possible into the base of the jaw.

But if you look at the actual physiology of the tongue, you'll discover that depressing the tongue in this way also depressed the larynx - you can even test it by opening your mouth as much as possible and trying to get the tongue as low into the base of the mouth as possible; when you do this, place your fingers around the base of your larynx.

It's tense as hell, right?

That's because the tongue partially controls the larynx, in the same fashion that you yawn - tongue forced low and back into the mouth, larynx depressed.

You'll also notice that singers/coaches that employ this method of forcing the tongue down as much as possible on every sound to "create space" always, always, always sing with a wide, spread mouth as they try desperately to raise the palate and fight the dark, covered sound that this creates.

This is also another misnomer you'll see from the methods that try to force you to lower your tongue in this way - they'll also encourage you to "smile wide" or "smile bright" because this tongue position creates an issue with freedom no only physically, but also in a frequency sense.

You literally can't sing bright or 'forward' enough with this forced larynx position - so you have to fake it.A

And you might even sound okay for a while.

Until you destroy your voice.

It's actually important to sing with a slight "hump" in the mid to back of your tongue to keep the root of the tongue from descending back into the throat, and also to form the overtone of each of your vowel sounds properly.

Why do you think "raised tongue" sounds like EE, OU and NG are so popular in voice coaching?

This raised tongue releases strain and these small sounds are the ultimate tongue tension singing remedy.

But it flows into your vowel sounds too.

Not only is there a whole subset of "raised tongue" vowels like AY, EE and OU in singing - even vowels that require a more centred tongue in the mouth in "lowered tongue" vowels like AH, AA and OH, the tongue hump is a feature in the back of the mouth.

Try it by singing an "NG" sound like the end of the word SING.

I realise that this is an improper positioning of the soft palate because this sound opens the velarpharyngeal port - but bear with me.

If we open this sound up into an AH vowel like the word "HARD", you'll notice that the hump created by the NG sound partially remains towards the back of the mouth even as you lower your tongue to form this AH based vowel. 

Oh yeah.... and there's no tongue tension, right?

Stop slamming your tongue into the base of your mouth and start forming your vowel sounds properly;

From the centre of the tongue back creates the "structure" of your vowel and the overtone by which we sing/create/sustain our formant, and the centre of the tongue forward creates the "clarity" of your vowel - ultimately your style and articulation choices.

Practice using this slight tongue hump in the mid to back of the mouth and you can thank me later when you're a completely strain free singer.

Here's an example of how I use the slight 'hump' tongue position through each vowel to create ease even in an intense rock song by Alice in Chains;