Who or what stops reading?
I am using adobe acrobat to read the pdf out loud on a mac. This is a document i am making for blind people.
Acrobat's "Read out loud" on Mac is not the most reliable part of the Acrobat software...
Most blind users would be using a different tool anyway, so this issue does not have to be a show stopper. The one thing you should ensure is whether the text is encoded properly. One way to find this out is to save out your document as an "Text (Accessible)". Open the exported text file in TextEdit - if you can find all the text, including these characters specific to Norwegian, you should be fine (with regard to readability of these characters).