docs: def _compute_energy(self, rate_wavsample):
      """retreive the speech / non speech labels for the speech sample given by the tuple (rate, wave signal)"""
  
      e = bob.ap.Energy(rate_wavsample[0], self.win_length_ms, self.win_shift_ms)
      energy_array = e(rate_wavsample[1])
      labels = self._voice_activity_detection(energy_array)
      # discard isolated speech a number of frames defined in smoothing_window
      labels = utils.smoothing(labels,self.smoothing_window)
  
      logger.info("After 2 Gaussian Energy-based VAD there are %d frames remaining over %d", numpy.sum(labels), len(labels))
      return labels