M4A Is Apple's Default Audio Format For Voice Memos And iPhone Recordings
M4A is the audio format Apple uses for Voice Memos on iPhone, iPad and Mac.
Every interview, meeting note, lecture or idea you record on an Apple device comes out as an M4A file.
It is compressed, high quality, and built for speech, which makes it the most common format people need to transcribe but the one least likely to work with older transcription tools that expect WAV or MP3.
Cockatoo handles M4A natively: upload the file straight from your device or paste a link from iCloud, Dropbox or Drive, and get a transcript in seconds.