1. A method for automatically marking a document to be read by a text-to-speech reader with voice type identifiers, said method comprising: identifying two or more voice types available to the text-to-speech reader, each voice type having a corresponding voice type identifier; identifying text elements within the document, wherein identifying text elements comprises marking gross structural subdivisions of text with a first set of sequenced tags, marking individual paragraphs of the text with a second set of sequenced tags, and marking text elements with a third set of sequenced tags to generate a hierarchical tree identifying the text elements; grouping similar text elements together, wherein the step of grouping comprises generating one or more clusters according to each identifiable topic of the document, syntactically parsing the document and subsequently performing text mining to determine which text elements in the document are similar, wherein similarity is based upon lexical affinities among the text elements; classifying the grouped text elements according to voice types available to the text-to-speech reader; and marking the classified grouped text elements within the document with corresponding voice type identifiers.