Have Voiceover read out just paragraph or sentence under cursor
While there is a contextual menu for Speech » Start speaking that will speak the selected text, it requires navigating several menus. If you want to be able to speak the selection without navigating menus, create an automator service that receives text in any application. Give it a single action: Run shell script. The shell script is utterly simple: /usr/bin/say (it will take the argument of what to say from stdin, which in this case will be the selected text). Save the service (I called it "Say paragraph").

Then, in System Preferences, you can assign this action a keyboard shortcut (I gave it  the keystroke ControlShift1). So triple click, then ControlShift1 and it speaks what's under the mouse pointer.