Welcome,
OpenEars can read text, so you would need to decide how to convert a file format that isn’t plain text into plain text to be used by OpenEars, and then you would need to split it up into small enough chunks of text that it wouldn’t be prohibitively slow for the enduser to listen to. NeatSpeech has built-in queuing to deal with keeping large amounts of text speaking fluently, but even with NeatSpeech you aren’t going to want to give it a 5-page Word file’s worth of text at once.