Although iCake says he can distinguish -и and -е in the ending position, and there actually are minor differences in pronunciation in different areas of the country, I believe the standard language tends to fully merge these unstressed phonemes. (Except for such cases as желание, сиденье, приключение and so on.)

Letters е/и in тучи, лиса, леса, кое-где, ниже and море aren't required to be pronounced differently, neither has one to able to distinguish them to understand Russian.