General American English has 12 vowel sounds.
On this chart, you will see the IPA symbol on
the left and the 7M symbol on the right.
The IPA provides symbols for individual phonemes only!
7M does the same. No diphthongs are represented by a
single character. The only sounds on this chart are
Pure Vowels aka 'monophthongs'.
The ? symbol represents the raised Short A sound
which is common in North America whenever the
Short A is followed by an 'N', 'M', or 'Ŋ'.
The raised Short A doesn't need a character in 7M
because it is used as an accent. The Dark L is represented by
the same 'L' character that is used for the Clear L
since one can tell which sound to use depending on
where the letter occurs in a word.
If you see a tilde between two symbols, it means
that the tongue position for the sound is either
unknown or uncertain.
Here is the new and simplified 7M definition of a 'vowel':
1. Produced by vocal chords.
2. Exits the mouth or mostly mouth but never exclusively the nose.
3. Is not combined with sounds generated by other mouth parts (pops, clicks, hisses, whistles etc)
4. Can be sustained until you run out of breath.
5. Remains consistently the same sound from beginning to end no matter how long you sustain it.
