code: def mel2hz(mel):
      """Convert a value in Mels to Hertz
  
      :param mel: a value in Mels. This can also be a numpy array, conversion proceeds element-wise.
      :returns: a value in Hertz. If an array was passed in, an identical sized array is returned.
      """
      return 700 * (10 ** (mel / 2595.0) - 1)
  
file_path: python_speech_features/python_speech_features/base.py
imports: from __future__ import division
  import numpy
  from python_speech_features import sigproc
  from scipy.fftpack import dct
label_desc: Use image node_id 7 for calling a global function with example usage: mel2hz(mel) and returns: unknown