diff --git a/pyrato/dsp.py b/pyrato/dsp.py
index 56eee764..cc1aa9c8 100644
--- a/pyrato/dsp.py
+++ b/pyrato/dsp.py
@@ -88,7 +88,7 @@ def estimate_noise_energy(
         shape of the input Signal.
     """
 
-    energy_data = preprocess_rir(
+    energy_data = _preprocess_rir(
         data,
         is_energy=is_energy,
         shift=False,
@@ -182,7 +182,7 @@ def _smooth_rir(
     return time_window_data, time_vector_window, time_vector
 
 
-def preprocess_rir(
+def _preprocess_rir(
         data,
         is_energy=False,
         shift=False,
diff --git a/pyrato/edc.py b/pyrato/edc.py
index f5024ac1..47ab2c23 100644
--- a/pyrato/edc.py
+++ b/pyrato/edc.py
@@ -292,7 +292,7 @@ def energy_decay_curve_truncation(
     shape = data.time.shape
     data = data.flatten()
 
-    energy_data = dsp.preprocess_rir(
+    energy_data = dsp._preprocess_rir(
         data,
         is_energy=is_energy,
         shift=time_shift,
@@ -451,7 +451,7 @@ def energy_decay_curve_lundeby(
     shape = data.time.shape
     data = data.flatten()
 
-    energy_data = dsp.preprocess_rir(
+    energy_data = dsp._preprocess_rir(
         data,
         is_energy=is_energy,
         shift=time_shift,
@@ -607,7 +607,7 @@ def energy_decay_curve_chu(
     shape = data.cshape
     data = data.flatten()
 
-    energy_data = dsp.preprocess_rir(
+    energy_data = dsp._preprocess_rir(
         data,
         is_energy=is_energy,
         shift=time_shift,
@@ -756,7 +756,7 @@ def energy_decay_curve_chu_lundeby(
     shape = data.time.shape
     data = data.flatten()
 
-    energy_data = dsp.preprocess_rir(
+    energy_data = dsp._preprocess_rir(
         data,
         is_energy=is_energy,
         shift=time_shift,
@@ -930,7 +930,7 @@ def intersection_time_lundeby(
     # Dynamic range 10 ... 20 dB
     use_dyn_range_for_regression = 20
 
-    energy_data = dsp.preprocess_rir(
+    energy_data = dsp._preprocess_rir(
         data,
         is_energy=is_energy,
         shift=time_shift,
@@ -1094,7 +1094,7 @@ def _intersection_time_lundby(
     noise_estimation : float
         The energy of the background noise.
     energy_data : np.ndarray
-        Data returned by ``pyrato.dsp.preprocess_rir``.
+        Data returned by ``pyrato.dsp._preprocess_rir``.
     time_vector_window : ndarray
         The time vector of the smoothed data obtained from
         ``pyrato.dsp._smooth_rir``.
diff --git a/tests/test_data/generate_test_data.py b/tests/test_data/generate_test_data.py
index cb200873..702a8aba 100644
--- a/tests/test_data/generate_test_data.py
+++ b/tests/test_data/generate_test_data.py
@@ -76,19 +76,19 @@
 noise_energy_2D = pyrato.estimate_noise_energy(
     rir_array, interval=[0.9, 1.0], is_energy=False)
 
-preprocessing_1D = pyrato.dsp.preprocess_rir(
+preprocessing_1D = pyrato.dsp._preprocess_rir(
     rir_array[0], is_energy=False, shift=False, channel_independent=False)
-preprocessing_2D = pyrato.dsp.preprocess_rir(
+preprocessing_2D = pyrato.dsp._preprocess_rir(
     rir_array, is_energy=False, shift=False, channel_independent=False)
 
-preprocessing_time_shift_1D = pyrato.dsp.preprocess_rir(
+preprocessing_time_shift_1D = pyrato.dsp._preprocess_rir(
     rir_array[0], is_energy=False, shift=True, channel_independent=False)
-preprocessing_time_shift_2D = pyrato.dsp.preprocess_rir(
+preprocessing_time_shift_2D = pyrato.dsp._preprocess_rir(
     rir_array, is_energy=False, shift=True, channel_independent=False)
 
-preprocessing_time_shift_channel_independent_1D = pyrato.dsp.preprocess_rir(
+preprocessing_time_shift_channel_independent_1D = pyrato.dsp._preprocess_rir(
     rir_array[0], is_energy=False, shift=True, channel_independent=True)
-preprocessing_time_shift_channel_independent_2D = pyrato.dsp.preprocess_rir(
+preprocessing_time_shift_channel_independent_2D = pyrato.dsp._preprocess_rir(
     rir_array, is_energy=False, shift=True, channel_independent=True)
 
 smoothed_rir_1D = pyrato.dsp._smooth_rir(
diff --git a/tests/test_dsp.py b/tests/test_dsp.py
index 528541cc..2b2a4e4f 100644
--- a/tests/test_dsp.py
+++ b/tests/test_dsp.py
@@ -105,7 +105,7 @@ def test_preprocessing_1D():
         os.path.join(test_data_path, 'analytic_rir_psnr50_1D.csv'),
         delimiter=',')
     rir = pf.Signal(rir, 1)
-    actual = dsp.preprocess_rir(
+    actual = dsp._preprocess_rir(
         rir,
         is_energy=False,
         shift=False,
@@ -123,7 +123,7 @@ def test_preprocessing_2D():
         delimiter=',')
     rir = pf.Signal(rir, 1)
 
-    actual = dsp.preprocess_rir(
+    actual = dsp._preprocess_rir(
         rir,
         is_energy=False,
         shift=False,
@@ -141,7 +141,7 @@ def test_preprocessing_time_shift_1D():
         delimiter=',')
     rir = pf.Signal(rir, 1)
 
-    actual = dsp.preprocess_rir(
+    actual = dsp._preprocess_rir(
         rir,
         is_energy=False,
         shift=True,
@@ -164,7 +164,7 @@ def test_preprocessing_time_shift_2D():
         os.path.join(test_data_path, 'preprocessing_time_shift_2D.csv'),
         delimiter=','))
 
-    actual = dsp.preprocess_rir(
+    actual = dsp._preprocess_rir(
         rir,
         is_energy=False,
         shift=True,
@@ -184,7 +184,7 @@ def test_preprocessing_time_shift_channel_independent_1D():
             'preprocessing_time_shift_channel_independent_1D.csv'),
         delimiter=','))
 
-    actual = dsp.preprocess_rir(
+    actual = dsp._preprocess_rir(
         rir,
         is_energy=False,
         shift=True,
@@ -203,7 +203,7 @@ def test_preprocessing_time_shift_channel_independent_2D():
             'preprocessing_time_shift_channel_independent_2D.csv'),
         delimiter=','))
 
-    actual = dsp.preprocess_rir(
+    actual = dsp._preprocess_rir(
         rir,
         is_energy=False,
         shift=True,