We have added a new download to www.chineseocw.com . This PDF (with embedded voice files) is all you need to master pinyin pronunciation. We have the entire pinyin chart with sound files embedded in a PDF that may downloaded for free, at this time. We have included a section to clarify some of the confusing points, such as the pinyin spellings that have more than one pronunciation. (i.e. the “uan” in “guan” is different that the “uan” in “yuan” and a few others) All of the examples have voice recordings embedded in the examples.