How can I apply an audio effect to a recorded audio?

I want to re开发者_运维百科cord a sample from the microphone, then I want to play the recorded file maximizing the volume and apply some audio effect, like modifing sample rate or addind an echo.

Waht is the best way? is there an example?

You can make use of AudioTrack & AudioEffect Android Java classes. Only catch is that you have to feed PCM samples to AudioTrack for playout.

Waht is the best way?

There is nothing built into Android for this sort of audio file modifications. You will need to either find a Java library for it or a C/C++ library and apply it using the NDK.