To keep the original filename when sending audio in the future, you can send the file as a instead of an Audio file.
If you are looking for this specific file, it is likely stored in one of two places on your device: Download AUD 20200709 WA0020 mp3
: Indicates this is an audio file (rather than a voice note, which typically starts with "PTT"). To keep the original filename when sending audio
: The unique identifier for that day. WA stands for WhatsApp, and 0020 means it was the 21st audio file (starting from 0000) processed on that specific date. Where to Find and Download It WA stands for WhatsApp, and 0020 means it
: The date the file was saved or received, formatted as YYYYMMDD (July 9, 2020).
The name follows a strict structure used by the WhatsApp media management system: