code: def stereo_to_mono(signal):
      """
      This function converts the input signal
      (stored in a numpy array) to MONO (if it is STEREO)
      """
  
      if signal.ndim == 2:
          if signal.shape[1] == 1:
              signal = signal.flatten()
          else:
              if signal.shape[1] == 2:
                  signal = (signal[:, 1] / 2) + (signal[:, 0] / 2)
      return signal
  
file_path: pyAudioAnalysis/pyAudioAnalysis/audioBasicIO.py
imports: from __future__ import print_function
  import os
  import glob
  import aifc
  import eyed3
  import ntpath
  import shutil
  import numpy
  from pydub import AudioSegment
  from scipy.io import wavfile
label_desc: Use image node_id 6 for calling a global function with example usage: stereo_to_mono(signal) and returns: signal