The visual nature of mathematical notation has made it too difficult to distinguish between content and presentation. While it may be possible for some simple cases, like single-variable calculus where notation is centuries old and common, modern mathematicians often invent their own notation for their immediate needs. Current Screen Readers are simply not designed to deal with this sort of input. Unfortunate as this is, it is the reality of the situation. The difficulties in presenting mathematics in an auditory modality are daunting.
Mathematical notation is designed for visual elegance.
In doing so, mathematicians use a two-dimensional notation. This includes the extensive use of superscripts and subscripts, elements layered on top of each other, hats and arrows, etc. This sort of problem becomes immediately visible when one attempts to read a two-dimensional matrix aloud. In these sorts of situations, the content of the expression is quickly obscured by the sheer mass of formatting information. In general, with no assumptions about context, an automated process can do no better than simply read a mathematical expression symbol by symbol.