If you recorded audio outside Grape, you can keep it with the note it belongs to.
Adding audio on desktop
Type / and choose Audio, then pick a file or paste a URL. You can also drag an audio file into the editor. The file becomes a player card inside the note.
On mobile
Inserting audio files is desktop only for now, but audio added on desktop plays fine on the phone. To capture audio on mobile, use the built in voice recorder instead.
Transcribing
Any audio card can be transcribed the same way as a recording made in the app, see Transcribe a recording or audio file. That turns an hour of interview audio into text you can search and quote, and Identify speakers splits it by who was talking.
Where audio lives
Audio files are stored with the note in your local library, and they sync along with everything else if sync is on.