How many special symbols are there for vowel sounds?

There are 14 commonly used symbols and 13 less commonly used symbols for vowel sounds.

There are a number of vowel sounds. The Link lists more than 20 of them for English. This does not include the various French, Spanish and Scandanavian accents or the additional volwel letters in the Greek and Cyrillic alphabets. Answer: There are actually 5, according to the Thorndike Barnhart Dictionary, which is what my school program recommended as a reference.