The symbol is called a “schwa” (pronounced w). This neutral vowel sound is found in unstressed syllables. All five English vowels, as well as the semi-vowel Y, are sometimes pronounced as a schwa.
Click on the sample words to listen to the sound files. The letter pronounced as a schwa is in bold.
cap a ble
en e my
incred i ble
gall o p
foc u s
vin y l
Note: when a word ends with (consonant + l + e), the sound of the (l+e) is actually a schwa + l sound (–l).