Many third-party voice memo or call recording apps use this naming convention for active recordings.
Because these are often "temp" files, they may not play in standard apps like iTunes or Spotify if the recording app crashed before saving the final metadata. Common Sources of "RecordTMP" Files RecordTMP (32) m4a
How to Recover Corrupted Audio Files
Apps like GarageBand or Audacity may create .tmp or RecordTMP files while you are recording to ensure data isn't lost if the program closes unexpectedly. How to Access or Fix the File Many third-party voice memo or call recording apps
If the file won't play, it is likely missing its "header" (the data that tells a player how long the audio is). You can try these methods: RecordTMP (32) m4a