code: def test_loudness_normalization_multichannel(self):
      samples = np.random.uniform(
          low=-0.2, high=-0.001, size=(3, 8000)
      ).astype(np.float32)
      sample_rate = 16000
  
      augment = LoudnessNormalization(min_lufs=-32, max_lufs=-12, p=1.0)
      processed_samples = augment(
          samples=samples, sample_rate=sample_rate
      )
      gain_factors = processed_samples / samples
      assert np.amin(gain_factors) == pytest.approx(
          np.amax(gain_factors)
      )
      assert processed_samples.dtype == np.float32
  
file_path: audiomentations/tests/test_loudness_normalization.py
imports: import pytest
  import numpy
  from numpy.testing import assert_almost_equal
  from audiomentations import LoudnessNormalization
label_desc: Use image node_id 4 for calling the TestLoudnessNormalization obj's underlying member method code with example usage: obj.test_loudness_normalization_multichannel() without return types