Special text-to-speech synthesizers exist that allows users to create an audio (such as standard PCM audio / WAV format) with a speech from a saved text file, or document but they are usually pretty expensive. And even that will in most cases require manual tweaking during the process because otherwise the audio would not be perfect.
Which means that although you can find text-to-speech software, they are not just magical docx to wav converters that works with single click.