Help with app, which will stream audio from mic to speaker/headphones

Hi , well, I wanna ask you all some questions, I m new to Android and I want to make app for my school work, which will stream audio direct from mic to earphones, so my questions are :

1. on which version of android i should do it (i heard that on JB we can reach about better latency )
2. which methods and classes i should use in programming (i am new to android and i want to learn , so can you advice me some sources ? )
3.is there any already coded source code which i can use for this? I googled a lot but codes i found was not working for me .


Thank you for answers or some sources for learning more about real-time audio, or anything helpful ,