I used an Olympus audio recorder. This was wonderful as I could record whilst walking, although I did need to learn how to protect it from wind. I did vary, some days forgetting abut it and doing a few big blasts, other days doing 30-40 small recordings.
fields:
date – file name
nos_files — number of audio files recorded that day
url – url of human readable directory listing
csv_url – url of CSV meta file for the day (see below)
json_url – identical information in JSON format
identical data in JSON format
The individual day’s audio data CSV and JSON files have the following fields:
name — file name
timestamp — UNIX timestamp of file time
date — date of recording — should be the same as date of meta file
time — time of day of the recording
size — size of recording in bytes
url — url of the mp3 file