Imagine a young woman (the witness) standing on the side of a main road. She sees some commotion across the street. On the opposite side of the road to her she sees an old man and hears him shout "The bank is being robbed!", as a young man runs out of a building and away down the street. The old man is never found (and so cannot appear in court to repeat what he said), but the woman repeats what she heard him say. Such a statement would be considered trustworthy for the purpose of admission as evidence because the statement was made concurrently with the event and there is little chance that the witness repeating the hearsay could have misunderstood its meaning or the speaker's intentions.