code: def apply_inv_preemphasis(self, x):
      if self.preemphasis == 0:
          raise RuntimeError(" [!] Preemphasis is set 0.0.")
      return scipy.signal.lfilter([1], [1, -self.preemphasis], x)
  
imports: import librosa
  import soundfile
  import numpy
  import scipy.io.wavfile
  import scipy.signal
  from TTS.tts.utils.data import StandardScaler
label_desc: Use image node_id 11 for calling the AudioProcessor obj's underlying member method code with example usage: obj.apply_inv_preemphasis(x) and returns: scipy