Use these free tools to extract the audio from an mp4 recording and transcribe it into a Word document.

Step 1 is to extract the audio to an mp3.
Step 2 is to transcribe the audio using Word.

Step 1. Use VLC Media Player to extract the audio to an mp3 file

• Click Media > Convert/Save
  
• Click the Add button and browse to select the file.
  
• Click Convert/Save to bring up the Convert window. Set the Profile to Audio-MP3 and click the wrench icon.
  
• On the Enscapsulation tab, select RAW and then click Save.
  
• Back on the Convert window, set the Destination file by clicking Browse. You can change the existing name by changing the end to mp3.
  
• Now click Start and wait for it convert. The main VLC Player window will show a progress bar, as if you were playing the file.
  
• After it's done, look in the destination folder to find your mp3 file.

Step 2. Use Microsoft Word Online to upload and transcribe the mp3 file