how to clear background sound of an animation

[znchb]

#the following program try to clean the animation-teacher and the sound,
#but I can't perform the later one, could you please help me? Thanks
import viz
import vizact
viz.go()
viz.clearcolor(viz.SKYBLUE)
viz.add('tut_ground.wrl')

teacher = viz.add('c:\\Program Files\\WorldViz\\Vizard30\\resources\\vcc_female.c fg')
teacher.translate(1,1,1)
viz.MainView.translate(0,2,-10)
teacher.setEuler(-180,0,0)
teacher.state(14)
#speech = vizact.speak('c:\\Program Files\\WorldViz\\Vizard30\\resources\\carousel.wav ')
teacher.addAction(vizact.speak('c:\\Program Files\\WorldViz\\Vizard30\\resources\\carousel.wav '))

def clean():

teacher.clearActions()#vizact.speak)
teacher.remove()

vizact.onkeydown(' ', clean)