Comment 10 for bug 253854

phonon development files need to be changed to be put under /usr/include/qt4/ instead of just under /usr/include. QMake will not work properly otherwise.

In a qt project file, you are supposed to add a line

QT += phonon

To include phonon support for your program. What this does is adds /usr/include/qt4/phonon to the include path. Therefore the standard way of creating QT applications is not supported by the current locations of libphonon-dev. This should definitely be fixed.