A scene may let us hear an event before showing what caused it. The interval can be brief, but it gives the audience time to imagine an explanation. Choose a moment when a sound begins outside the visible frame and follow the sequence without jumping ahead.
Write down the first inference
What did you initially think you heard? A vehicle, a machine, a person moving nearby? Describe the audible qualities that prompted that guess rather than naming the source with knowledge gained later.
Then identify when the image provides more information. It might reveal the source directly, show a character reacting, or leave the sound unexplained. These are different outcomes and should not be collapsed into one description.
Compare knowledge across the scene
Does a character recognise the sound before you do? Their response may guide your interpretation, but it does not always settle the matter. Watch for the difference between what is heard, what someone believes, and what the film confirms.
End your note at the moment the relationship changes. “I first took the noise for footsteps; the next shot showed a loose object moving” is a useful account. It explains a small piece of audience experience without needing to label every sound as a clue or a deliberate deception.