You can trust very much in Spanish accents. Almost 99,9999% are said as the accent marks. But we have a very few words (really very very few) that can be said with two different steresses. One of this is "período" or "periodo", both forms are admitted and if the speaker usually says "periodo" and it is writed "período" he will say without the accent (we really don't look at the accents for known words when we are reading).
PD: I hear the stress in the fist "o", not in the "e", but the word is really awfull said.