if you have a smartphone, you can use a setting in the 'Accessibility' System Settings to read selected text for you.
1) enable setting
2) open pdf
3) select text; have it play back
4) when done, go back and turn the setting off
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If your pdf reader doesn't allow you to select the text, you can always convert the PDF to a DOC or TXT in Libreoffice. Personally, I've been using tesseract to convert pictures to text and then having it read back to me.