How to process sound in Java for Android?

Folks,

As a start, I would l开发者_运维问答ike to develop a Java application that will act as a guitar tuner. The application should listen to what I play on the guitar and tell me the notes I played. I am wondering what level of support is provided by Android SDK. Do I need any other open source library? Any pointers would be appreciated.

Thank you in advance for your help.

Regards,

Peter