I was taught that the vowels in Spanish are always pronounced the same in contrast to the English language. For this reason, I always pronounced
/a/ in "pan" as the same as
/a/ in "papa"—this is very similar to the pronunciation of "father" in English. However when I listen to the pronunciation on "pan" here (http://www.spanishdict.com/translate/pan), it sounds very close to the English word "pan"; yet "papa" sounds like the way I pronounced it (http://www.spanishdict.com/translate/papa).
Wikipedia has an article (https://en.wikipedia.org/wiki/Spanish_phonology) that touches on the idea that the vowels in the Spanish language are associated with various allophones. Are my auditory senses deceiving me, or is
/a/ in "pan" being pronounced differently than
/a/ in "papa"?
Is there a rule that I should learn that aids me in determining the "correct" way to pronounce
/a/ in a word? For example, if
/a/, then pronounce
/a/ similar to the way I'd pronounce the "a" in "pan" in English?