code: def zero_crossing_rate(audio, frame_length=1024, hop_length=512):
      zero_crossings = np.sum(np.abs(np.diff(np.sign(audio))) / 2)
      total_frames = 1 + int((len(audio) - frame_length) / hop_length)
      return zero_crossings / total_frames
  
imports: import logging
  import os
  import re
  from glob import glob
  from typing import Dict, List
  import librosa
  import numpy
  import torch
  import torchaudio
  import tqdm
  from encodec.utils import convert_audio
  from scipy.special import softmax
  from torch.nn import functional
  from TTS.tts.layers.bark.hubert.hubert_manager import HubertManager
  from TTS.tts.layers.bark.hubert.kmeans_hubert import CustomHubert
  from TTS.tts.layers.bark.hubert.tokenizer import HubertTokenizer
  from TTS.tts.layers.bark.load_model import clear_cuda_cache, inference_mode
label_desc: Use image node_id 7 for calling a global function with example usage: zero_crossing_rate(audio, frame_length, hop_length) and returns: unknown