text: import numpy as np
  from scipy import signal
  
  
  def pre_emphasis(signal_batch, emph_coeff=0.95, axis=-1) -> np.array:
      """
      Pre-emphasis of higher frequencies given a batch of signal.
      Args:
          signal_batch(np.array): batch of signals, represented as numpy arrays
          emph_coeff(float): emphasis coefficient
          axis:
      Returns:
          result: pre-emphasized signal batch
      """
      return signal.lfilter([1, -emph_coeff], [1], signal_batch, axis=axis).astype(dtype=np.float32)
  
  
  def de_emphasis(signal_batch, emph_coeff=0.95, axis=-1) -> np.array:
      """
      De-emphasis operation given a batch of signal.
      Reverts the pre-emphasized signal.
      Args:
          signal_batch(np.array): batch of signals, represented as numpy arrays
          emph_coeff(float): emphasis coefficient
          axis:
      Returns:
          result: de-emphasized signal batch
      """
      return signal.lfilter([1], [1, -emph_coeff], signal_batch, axis=axis).astype(dtype=np.float32)
  