A hex editor like 0xED on Mac can reveal that the file needs its header stripped. How to Recover "01 90 Proof.m4a" (And Similar Files)
The data is usually there, just inaccessible. 01 90 Proof.m4a
Install faad2 via Homebrew ( brew install faad2 ) and try converting the raw file, adjusting the sample rate if necessary. A hex editor like 0xED on Mac can
If you are seeing a .m4a file that won’t play, you are likely dealing with a corrupted header or a premature shutdown of the recording app. What is a .m4a File? 01 90 Proof.m4a