Looking for an experienced developer who has worked with audio recording on Android. The app has only on Button (on/off) switch. If it is on, then record from the MIC/default audio-in device, revert the amplitude and send it immediatly to the speakers/audio-out.
The app has to work also in the background, so that the user can leave the mobile device on the table without an active screen.
The big challenge seems to be to get the MIC and record small enough buffer values to apply the transformation and send it to the audio out in realtime.
How to do adaptive noise cancellation can be viewed in this exercise:
Better audio control can be achieved by the OpenSL ES: