code: def main():
      parser = argparse.ArgumentParser()
      parser.add_argument(
          "--input_manifest",
          type=str,
          required=True,
          help="clean test set",
      )
      parser.add_argument(
          "--noise_manifest",
          type=str,
          required=True,
          help="path to noise manifest file",
      )
      parser.add_argument(
          "--out_dir",
          type=str,
          required=True,
          help="destination directory for audio and manifests",
      )
      parser.add_argument(
          "--snrs", type=int, nargs="+", default=[0, 10, 20, 30]
      )
      parser.add_argument("--seed", type=int, default=42)
      parser.add_argument("--num_workers", default=1, type=int)
      parser.add_argument("--sample_rate", default=16000, type=int)
      parser.add_argument(
          "--attenuation_factor",
          default=0.8,
          type=float,
          help="Attenuation factor applied on the normalized noise-added samples before writing to wave",
      )
      parser.add_argument(
          "--save_noise",
          default=False,
          action="store_true",
          help="save the noise added to the input signal",
      )
  
      args = parser.parse_args()
      global sample_rate
      sample_rate = args.sample_rate
      global att_factor
      att_factor = args.attenuation_factor
      global save_noise
      save_noise = args.save_noise
      global rng
      rng = args.seed
      num_workers = args.num_workers
  
      add_noise(
          args.input_manifest,
          args.snrs,
          args.noise_manifest,
          args.out_dir,
          num_workers=num_workers,
      )
      create_manifest(
          args.input_manifest,
          args.noise_manifest,
          args.snrs,
          args.out_dir,
          args.save_noise,
      )
  
file_path: NeMo/scripts/dataset_processing/add_noise.py
imports: import argparse
  import copy
  import json
  import multiprocessing
  import os
  import random
  import numpy
  import soundfile
  from nemo.collections.asr.parts.preprocessing.perturb import NoisePerturbation
  from nemo.collections.asr.parts.preprocessing.segment import AudioSegment
label_desc: Use image node_id 5 for calling a global function with example usage: main() without return types