First thing I would do is try alternatives to TextAloud - some can read the PDF files direct ==>>
TextAloud Alternatives and Similar Software - AlternativeTo.net
If you are starting with PDF formats try to find an alternative, PDF is the worst place to start.
If you're stuck with PDF, search MR for 'Convert PDF'. You'll discover that are many ways to do it, but there is no optimal way for all PDFs, and many conversions will require more than one tool.
If you can get the book into EPUB/AZW3/KEPUB format there is a TTS to MP3 calibre plugin that may be of interest.
BR