Android doesn’t have a low-latency audio API. The current bug for this is 3434.
What does this mean for me? Since the Iambic Keyboard would want to play the tones at the same time as the paddles are flashing, and not up to 300ms later, that means that I can’t do audio until this is resolved. The good news for me is that the vibrator is pretty low-latency, which makes it an acceptable substitute for me. This does mean that I can’t make a music game for Android, though.