The downloaded mp3 files will be in a zip folder. Simply select the zip folder with a left click of the mouse than right click the zip folder and choose "extract all" from the menu choices. Then follow the instructions.
You can create a play list in itunes (for Apple devices )or Media player (for Microsoft devices) and then play the chapters as music recordings. It is possible to have different voices but you would need to invest in a program called text aloud and request the audio files in text, which this program would convert to mp3. This is a fairly simple project if you wish different voices to listen to our books. Use the contact us link at the bottom of the page to make a request for the audio files or information where to purchasae TextAloud.