text: Title: audio file as input parameter for model.transcribe works well but ndarray-typed parameter captured with sounddevice does not work
  Body: `model.transcribe` works well when I use an audio file as an input parameter. But when I use sounddevice to record a period of speech and save the speech result as ndarray  and send it directly for `model.transcribe` , it cannot recognize speech. 
  But I save the speech recorded by sounddevice as an audio file and then use this file as input paramter for `model.transcribe` , the speech can be recognized. What is the problem? Is there any specific format requirement for ndarray parameter? 
     