The following instructions are for MacOS Sierra (10.12.16).

You can activate Read Aloud (or Text to Speech) on your Mac so that it reads documents (word, pdf, etc.) or websites when you select certain keys.

Apple Icon > System Preferences > Accessibility > Speech > Speak Selected Text When the Key is Pressed

You can also change the key that activates Read Aloud. I set mine to Control-Shift-R, but you could also do something easier like Control-R.

I found some variability re: whether it worked on different apps. On an earlier version of this version of Read Aloud, for instance, it could read books in my Kindle app. Now that doesn’t seem to work. The Kindle app for Mac has it’s own Text to Speech (look under ‘Tools’), but there is no speed control, yet.

Hopefully they are working on optimizing this function.

There are also free text to speech or read aloud apps to simplify activating read aloud on Windows and Android devices

Do you have readers that you prefer?  If so, please share!