Enable the Text-To-Speech feature in System Preferences, Dictation and Speech. Select the “Speak selected text when the key is pressed” check box. Highlight the text you want to hear, then click the Option-Esc keystroke to listen to it. To stop listening to the text, click the Option-Esc keystroke again.
VoiceOver is another feature built into a MAC. It is for blind users because it is controlled by the keyboard, but you can use it too. Please click the following link to learn how to use VoiceOver Keystrokes.