Re: How do humans talk?

How do humans talk?

The basic physics of the human voice works much like the musical 
instruments of the violin family. In the violin, sound is produced by 
causing a string to vibrate over a resonance chamber. The pitch of the 
sound can be altered by changing the tension on the string – a tighter 
string produces a higher pitch, a looser string produces a lower pitch. 
The quality of the sound changes based on how you vibrate the string (bow 
or pluck it) and how you modulate the tone (vibrato). The volume of the 
sound (or loudness) changes with the force applied when bowing or plucking 
the strings. Although the principles remain the same, the tone can also be 
made lower by increasing the thickness of the string (going from the thin 
high E string to the thicker low G string on the violin), by increasing 
the size of the resonance chamber (going from a violin to a viola), or 
both (going to the cello or bass).

The basic sound of the human voice is caused by passing air over two 
vibrating ligaments (the vocal chords). The tension on the vocal chords 
can change to produce a higher or lower tone. The sound is further 
modulated by using the larynx (voice box), mouth and nose as resonance 
chambers. The size of the resonance chamber by can be adjusted by 
positioning the tongue and lips and by opening and closing your mouth. 
Finally, the quality of the airflow is adjusted using your lips and tongue 
to produced a smooth sound (like the letter m) versus an abrupt sound 
(like the letter b). The volume (or loudness) of your voice is adjusted by 
increasing or decreasing the amount of air passing through the vocal 
system. 

Reaching puberty changes the instrument of your voice. The vocal chords 
become thicker and the resonance chamber becomes larger, resulting in a 
lower tone. Why does the voice crack during puberty? If you have every 
played the violin (of heard someone who was learning to play), you will 
hear that simple mistakes can change a mellow toned instrument into a 
squeaky disaster. A boy going through puberty is learning to use the new 
qualities of his voice, and makes occasional mistakes. Men, in general, 
have a lower voice than women, because men, in general, are large animals. 
Therefore, men tend to have thicker vocal chords and larger resonance 
chambers.


The picture comes from the Sobotta Atlas of Human Anatomy. The image is 
looking down the throat into the larynx. The arrow points to one of the 
two vocal chords.