2 soundcards maybe??? (Score 3, Interesting)

If the reason you dont want sounds is because your say listening to music via another app you could get a 2nd sound output device (say a cheap usb 'soundcard') make that primary ound output and not plug anything into it. Then set your sound app to use the other soundcard that has speakers on it.

You shouldn't have to goto these lengths to do it, but it would work.