This version of Sounds(one of my scenarios) is broken. "How?" you may ask, and the answer is... you'll see. Press either the left or right arrow key to discover the magic.
The problem is you are creating multiple instances of the GreenfootSound class (and probably using 'Greenfoot.playSound(String filename)' to play them. Create only one GreenfootSound object either in the world constructor or when declaring the field that is to hold it:
private GreenfootSound sound = new GreenfootSound(filename);
Then use:
sound.play();
to play the sound.
A new version of this scenario was uploaded on 2017-05-19 01:27:13 UTC
Made scenario even more broken...
2017/5/17
2017/5/18
2017/5/18
2017/5/18