LightSpeech is a text-to-speech application for macOS 10.8 and later.
You select text in any app, and send it to the LightSpeech app which reads it out for you. LightSpeech can help you read long articles, chapters and even entire books. And the app keeps track of your reading statistics which may even motivate you to read more.
Visit the product page to download a fully-functional trial version.
LightSpeech is an excellent companion to PDFSpeech. While the latter enables text-to-speech in PDFs, LightSpeech works with any macOS application where you can select text.