If your larynx goes up for high notes you will have problems with high notes. If it goes down for low notes,
they will sound "muddy" or "thuddy".
Your diaphragm causes air to enter your lungs, when it contracts (it
is a muscle). The oblique and transverse abdominal muscles, the rectus (not the rectum), the triangularis sterni, and the
internal intercostals (they are between the ribs) PUSH out your air.
If you have to push out air when you
are singing a high note, then you are hyperadducting your vocal folds (cords). This is usually a result of an elevated larynx.
There are exercises to work the sternothyroid and sternohyoid muscles which can teach them to overcome the upward movement
of the larynx.
Your abdomen has no air pockets.
Your diaphragm "pulls" in air. Read above.
is from swelling or irritation or worse-nodules, polyps, or cancer. It is not normal. If it persists, see your doctor and
consider vocal training.
Sound comes out at about 750 miles per hour. It is 1/2200 second, more or less,
from the time that the sound is made until it exits your body. You do not have valves to stick it somewhere (except to make
a nasal sound).
Your diaphragm does not have the kind of nerves in it that allow you to feel it. You
may feel the organs that it presses against as it descends but the diaphragm doesn't have proprioceptive nerves in it.
tongue forms your vowel sounds. There are front (or forward) vowels and there are back vowels, described as such according
to the tongue's position. The tongue is most flat on "a", as in 'apple' and on "o", as in 'on'. If you sing with your tongue
down, you can make only those two vowel sounds.
There ARE some vowel sound alterations which can help with high notes sometimes.
Depending on the imagery. Imagery having to do with where sound travels is useless. You do not have valves
in your head that direct sound.