Panda 1.7 sound crackle - OpenAL

Well the working version:

from direct.showbase.ShowBase import ShowBase
from pandac.PandaModules import *
import struct

class MyApp(ShowBase):
    def __init__(self):
        ShowBase.__init__(self)

        source = UserDataAudio(11025,2)
        data = str()
        for x in range(11025*5*2):
            data += struct.pack('h',0) #only changed line
        source.append(data)
        source.done()
           
        sound = base.sfxManagerList[0].getSound(source)
        sound.play()

app = MyApp()
app.run()

So you see only one single line has changed. The clou was to provide the rawdata as signed short and not as unsigned short so I had to fix my importer-module.