How much more clear does it need to be? As Lykurg said, QSound can only play content from files on disk, it cannot play sounds encoded in the program's resources.

Qt Code: 
  1. //I know the following works
  2. QSound::play("C:/sound.wav");
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You need to give QSound the name of a disk file that has sound encoded in .wav format, and the file needs to be able to be found at run time - either it is in the program's current working directory or the location is specified using an absolute path (like the example above).