The entire text of Science and Health with Key to the Scriptures is available as a free audiobook for you to listen to online 24 hours a day. The recording runs on a continuous loop. That means it plays non-stop until the end of the book. Then it begins again.
If you do not hear any audio within 1 minute of clicking the Play button, refresh the page and try again. If you're having problems on an Apple mobile device try going here.