[REFACTOR] cleaned up nesting level/deep in SoundPlayer class

Change-Id: I1c1037fb6449bf8e931e029b8a8edf2fd377c985
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1377
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>