A memory becomes tidier every time you tell it. A notebook tends to remain inconveniently specific. Mine includes the shopping list, the window measurements, and three different accounts of the same Thursday. The ordinary details are the ones I find myself coming back to.
What belongs in a field note
Keep the place, sequence, and your interpretation separate. Write down what happened before the sound, what you heard, and what the room did afterwards. A useful description leaves room for another reader to reach a different conclusion.
Start with a recording
This was supposed to be a page about a small terrarium. It has become a record of visitors, unaccountable noises, and the increasingly elaborate explanations my household supplies for both. I have kept the notes in order. Mostly.
Listen to the sample collection and compare the notes. The labels concern the sounds; the stories concern the people who heard them.