have you included the Qt Multimedia kit?

Qt Code: 
  1. import QtMultimediaKit 1.1
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and in your pro file, i think you should include the following lines:

Qt Code: 
  1. CONFIG += MOBILITY
  2. MOBILITY += multimedia
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Also, you can only test playing your wav on an actual symbian device. If you run your program on desktop, an error will say that the Qt Multimedia Kit is not installed ( or something similar ). If you run on simulator, the error will say that the multimedia service is not available ( or something like that ).