Perceptual Short-term memory
Particularly amazing and crucial to recognizing words and sentences is what I would refer to as Perceptual Short-term memory, which lasts up to around 2 seconds.
Professors often speak 20 to 30 words in a sentence and then keep on rambling mindless of the fact that the listener must retain the whole litany of words in their order before the meaning of the sentence can be determined. What is more, Professors give little time for completion of this process, and keep the words coming for the next, and the next and the next sentence.
It seems almost inhumane, and yet students rarely yell, "Slow down!"
In fact in one class, where the speaking style of the instructor was such that he spoke at a rate of around one word a second, the students were literally falling asleep.