Question: FFT and iFFT not working

I'm trying to make a FFT from a 2s long input file by using the obsolete FFT-procedure, but strange thing is: No matter what first argument they receive (3, 2, 1, 0 even!) the result is always the same; even more strange is: Writing out the signal after the FFT it's exactly the same as before as if the FFT never would've happened.
What am I doing wrong?

restart;
with(AudioTools);
with(ArrayTools);
readlib(FFT);
clarinet := cat("C:/Documents and Settings/848380/Desktop/", "klar.wav");
x := Read(clarinet);
h := Array(1 .. 2^16, datatype = float[8], storage = rectangular, order = C_order);
ArrayTools[Copy](x, h);
setattribute(h, attributes(x));
hi := Array(1 .. 2^16, datatype = float[8], storage = rectangular, order = C_order);
FFT(0, h, hi);
iFFT(0, h, hi);
Write("C:/Documents and Settings/848380/Desktop/output.wav", h);