Specialized transcription services (VoiceBase for example) and solutions exist that offer users the way to trasform (transcript) the speech from an audio file, for examle in Adaptive Multi-Rate audio format (.amr), and save the words in a plain text format (.txt).
This may not always be perfect and usually requires some sort of manual post-editing, but it's pretty much what amr to text conversion represents.
Updated: October 6, 2022