I've been working on voice recently, and I think I figured something out
that really makes it more enjoyable. I have a nasal speaking voice, so
reasonably I also have a nasal singing voice. I started looking on
YouTube to find out more about it, and this excellent linguist really
opened my eyes to a lot of stuff - and I think I'm understanding it.
You got:
- larynx (voice box) contains the vocal folds
- pharynx (chamber behind your mouth and nasal cavity; leads down to the esophagus (food) and trachea (air)
- nasal cavity - giant space behind your nose
- mouth
When a pitch is activated within an acoustic chamber, there are
sympathetic frequencies that also resonate resulting in a full series of
notes (although they are difficult to hear individually) which thereby
create a very rich and unique combined sound - if you want to try it,
you can sing or just yell into a guitar's acoustic hole and you'll get
all the strings shaking just by the power of the fundamental note coming
out of your voice. Inversely, a synthesizer creating a SIN wave is
literally a single pitch without this series of overtones -
cleverly named "the overtone series". Going in the other direction, a
singer singing in a concert hall is actually a rich 'combined note' then
activating the overtones in the hall which makes the sound completely
new and rich all over again! Get it? A single note is actually not
just one frequency ringing - its a fundamental pitch (the loudest / one
you hear) accompanied by a bunch of other higher notes ringing together
(though weaker but adding lots of flavor). Its the shape, material, and
method of transmission to the acoustic chamber that creates different
sounding instruments, or noises, or any sound really. By the way I'm
just making all this up.
Lets get back to your mouth. When you sing or speak, the shape of your
mouth will amplify some of those sympathetic frequencies (they're called
partials or overtones) and will negate others - your tongue is the most
active participant in this process. When you say words like "Aw" or
"Oh", the jaws open and your tongue stays low down resulting in lots of
space in your mouth for resonance - extend the lips and you get an even
'deeper' / 'richer' tone because you're literally making the chamber
slightly bigger. When you say words like 'she' or 'is' the jaws can
stay closed and the tongue rises which results in relatively less space
in the mouth for resonance - this results in a disproportionate amount
of air being sent to the nasal cavity, which has a completely different
design with respect to the amplification / negation of those overtones.
I believe both the mouth and nasal cavity (or oropharynx and
nasopharynx) are used in singing, but use of one more than the other
results in a noticeable change.
The reason why the mouth technique is much more pleasing to the ear and stays in tune more easily is because more of those overtones are being amplified when the mouth is used vs. the nasal cavity. In fact, the acoustic chambers in your face are actually just filters of those sympathetic frequencies - and your nasal cavity eliminates a lot of them. The trick is to get those nasal sounding vowels and consonants back in the mouth - words like 'me' 'neighbor' and 'this' have to be actively directed to stay in the mouth. Words like 'law' or 'volume' are easier because the tongue is already down, and the vowel requires your jaws to be open. Try closing your jaws on law and it becomes 'luh' - or just try saying law all the way to a closed mouth hum, and the only place the sound can come out is the nose. So inversely, to sing 'me' you gotta try to imagine the word 'meh' coming out, and the result should be more open jaws and the tongue out of the way to create a nice balanced sound between the oropharynx and nasopharynx. At least I think so...