What is the dependencies error ?
On Osx, you can use the 'audio2ascii.sh' bash script, which is use by the pyplug, as standalone.
You use it like this:
$ ./audio2ascii audioFile fileCurve.ascii [x|y|xy] NatronProjectFps durationInFrames [CurveHeightInX] [CurveLenghtInY]
You need to install gawk sox as mentioned in the requirement
Hope it help.
PS: I haven't watch to audio2ascii and Natron since a lot of time. But, as i can see, some changes happened in the Natron python API, which i didn't follow, since last audio2ascii release (8 months ago). That's why some details in the code can make it no working anymore. But stand alone script to construct ascii curve should work.