Ideas for next step of Machine Learning I have completely followed the machine learning course on coursera Machine Learning by professor Andrew Ng 

Now I want to put my knowledge to action. Some ideas that I have include : 

-Voice synthesis
 -Voice recognition

But since the course did not focus specifically on application of machine learning in these domains, could some one point me to some other course or books that can get me started.
I would suggest you to check this excellent presentation by Li Deng (Microsoft Research). Many of the slides contain references to relevant research papers and even several interesting books on the topics of interest (it should be pretty easy to find). It might be also helpful to check references, listed in this research paper by Prof. Andrew Ng and his colleagues at Baidu Research. Finally, a focused Internet search will provide you with comprehensive list of resources for further research.