Comment 2 for bug 214876

And just to clarify for others this can be easily reproduced:

Simply mouseover a sound file until a tooltip would appear, and it will begin playing. Then press the delete key. It will continue playing.

Right clicking or using the context menu key, however, immediately terminates the playing of the file.

This bug can also manifest itself if you press SHIFT+DEL on the file, without moving your mouse cursor over the confirmation message that appears. If you just press enter, the file still plays.