"Speak selected text" reads whole document in Preview Recently I enabled Speak selected text when key is pressed feature in Accessibility menu.

It works well in Safari, Finder and other apps. But in Preview and other PDF readers like Skim, it acts wired. Although I selected a single word, it starts speaking from the first page of document, and if the first page contains only cover image, it says nothing. (silence)

It's macOS High Sierra with latest updates installed.
while the Preview is active select your text then on the top menue select "Edit" then select "Speech" then "Start speaking". You can create a keyboard shortcut for it by adding a shortcut key combination to the Keyboard in System Preferences:
 https://support.apple.com/kb/PH25377?locale=en_US