So in terms of uploading previously saved training data to Teachable Machine I believe it does allow you to open arbitrary data saved from other TM produced models etc if you have access to them. You just need to click on the 3 lines at the top left to access the file menu to do so. Eg on this page: Teachable Machine 2
Do this:

trm1533×1180 65.4 KB

Check out @lgusm suggestions for acessing the raw code of TM though and there is also a fun codelab on how to make your own Teachable Machine for images here - but as audio classification is an image problem it may also help you out:

  
      

      Google Codelabs
  

  
    

TensorFlow.js Transfer Learning Image Classifier  |  Google Codelabs 4

  In this codelab, you will learn how to build a “Teachable machine”, a custom image classifier that you will train on the fly in the browser using TensorFlow.js.