Audio transcription involves listening back to a recording of someone talking and typing what is said. It is commonly used for research interviews. There are tools available that can do this for you - although it will likely contain inaccuracies that you need to fix manually.
Transcribing tools:
- YouTube auto-transcribes videos in a number of languages.
- Download the transcript file from a YouTube video:
...
- One audio
- Audio playback and typing tool in one: http://ejb.github.io/2013/10/03/otranscribe.html