Speed up Waveform in LabVIEW

I would like to speed up sounds in LabVIEW to get chipmunk sounds. It seems to me this would be done by changing the dt for the waveform of the sound, thereby changing the time associated with each Y value, but that seems to have no effect. How is it done? And what does changing dt do? For reference, my VI is here, I am concerned about the "helium" and "heavy gas" cases.

Solution

The trick is in the output configuration of the Sound output VI. That actually controls the generation speed of the output:
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