Like many others, I have been baffled by what Paul Fellows was hoping to
achieve. The key is where he writes: 

 

> From brousing this forum, I came across ?convet mp3 to .txt file? started
by  John S Higgs. Ulrich Klauer suggested.

>             sox in.mp3 -t dat out.txt

 

The ".txt" extension has misled Paul. He assumes that given an audio input
file, SoX will produce a transcription (speech to text).

 

The example of course, merely writes a text file containing the value of
each sample contained within "in.mp3". Paul, that file will not help you in
the slightest with your chatbot project. SoX can do many things, but it
cannot, repeat *CANNOT* convert speech to text.

Please try the example "sox in.mp3 -t dat out.txt" and load "out.txt" into a
text editor. All should then become clear - and Jan Stary's blood pressure
will improve!