Stepmania/DDR like clapping sound when arrows hit the base line
This is due to the fact that Android does not support low latency audio. This means that there is a delay between the time when you are launching sound playback by the code and the time when the sound is actually gets played. This is most noticeable on all the "Musical instrument" apps where for example the drum sound comes 130 ms later than your actual hit on the touchscreen.This is a lot and you can clearly hear the delay. It would also mess up your accuracy.
To make things worse - the sound delay is different every time. So no, i can't launch the clap sound a bit earlier.
To get more info, you can read this official article