!</span> <span style="color: #87cefa;">pv-lp-wall-test</span> ((buf buffer) (size fixnum) (hop-size fixnum) amp)
  (with ((fft (make-fft size))
         (abuf (make-abuffer fft))
         (ifft (make-ifft size))
         (d-nbins (sample (abuffer-nbins abuf))))
    (<span style="color: #8deeee;">declare</span> (type sample d-nbins))
    (setf (fft-input fft) (buffer-play buf 1 0 t #'identity))
    (with-control-period (hop-size)
      (compute-ifft ifft (pv-lp-wall abuf (lag (lin-mouse-x 0 d-nbins) .02))))
