There is a VI called Snd Write Wave File. You would provide your Y data to it. The inputs would be either mono 8 bit or 16 bit so you might have to convert a sgl/dbl array first. You would also have to derive the sample rate from the x array and provide that to function. If your original sample rate is not one of the supported sound card formats, then some interpolation might be required. Could you provide more details on your x and y arrays and how they were acquired in the first place?