seems to work fine Skim, a free PDF viewer, might be of interest to you. It's scriptable and features an AppleScript command to extract the text from certain PDF pages. Once you've downloaded Skim, you can run this script:
tell application "Skim"
open (POSIX file "/path/to/PDF/document.pdf")
set the stuff to (get text for page 1 of document 1) as string --change 'page 1' to whatever page number you need
--if you want all the pages, just use 'every page'
say the stuff using "Fred" saving to file (((path to desktop) as string) & "audio.aiff")
How to count the number of spoken syllables in an audio file?
With these it helps The automatic segmentation of speech is an active scientific domain, meaning that there is no method that works perfectly. In 2009, de Jong and Wempe proposed a method to automatically detect syllables in a human speech signal using Praat. This methods compares well with man-made segmentation, and has been employed in many third-party scientific studies. You can find a detailed description of the method in their scientific article (pdf), along with an historical perspective on previously proposed methods. The Praat script per se and a couple of tutorials can be found on a dedicated website (www - speechrate).
Search for a particular spoken word in audio files