Spectral inversion of speech

Good day! How to make a spectral inversion of speech on Audacity?

Apply this code with the “Nyquist Prompt” (see: https://manual.audacityteam.org/man/nyquist_prompt.html)

(defun lowwall (sig hz)
  (dotimes (i 4 sig)
    (setf sig (lowpass8 sig hz))))

(defun hiwall (sig hz)
  (dotimes (i 4 sig)
    (setf sig (highpass8 sig hz))))

(defun bandpass (sig low high)
  (hiwall (lowwall sig high) low))

(let ((sig (bandpass *track* 50 7000)))
  (mult 3 (bandpass (mult sig (hzosc 8000)) 50 7000)))

Thanks.