When you import audio that has been saved at a frequency other than 11025 khz, 22050 khz, 44100 khz it will sound funny in our audio player. You will have to edit your sound file in Audacity and re-upload it to fix the problem. 
To change the frequency in Audacity do the following:

  1. Open the file in Audacity
  2. Change the Project Rate (bottom left corner) to 22050 Hz
  3. Click on File -> Export
  4. Choose a name
  5. Change file format to MP3
  6. Click Options, change Quality to 80kbps
  7. Re-import the new audio file to the lesson you created