I've tried right now. The pdf is in English. I've downloaded English voice, but it keeps reading with the Portuguese voice (so, it can't read properly).Hav you tried tried macOS built in text to speech?
Have your Mac speak text that’s on the screen
Press a keyboard shortcut to make your Mac speak text that’s on the screen.support.apple.com
Change the voice your Mac uses to speak text5. When you’re done adding voices, click OK.
6. Click the “System voice” pop-up menu, then choose a voice you added.