diff --git a/TTS/utils/audio.py b/TTS/utils/audio.py
index 154f1c53..c476065d 100644
--- a/TTS/utils/audio.py
+++ b/TTS/utils/audio.py
@@ -245,11 +245,11 @@ class AudioProcessor(object):
     ### DB and AMP conversion ###
     # pylint: disable=no-self-use
     def _amp_to_db(self, x):
-        return self.spec_gain * log_(np.maximum(1e-5, x), self.base)
+        return self.spec_gain * _log(np.maximum(1e-5, x), self.base)
 
     # pylint: disable=no-self-use
     def _db_to_amp(self, x):
-        return exp_(x / self.spec_gain, self.base)
+        return _exp(x / self.spec_gain, self.base)
 
     ### Preemphasis ###
     def apply_preemphasis(self, x):
@@ -429,12 +429,12 @@ class AudioProcessor(object):
     def dequantize(x, bits):
         return 2 * x / (2 ** bits - 1) - 1
 
-def log_(x, base):
+def _log(x, base):
     if base == 10:
         return np.log10(x)
     return np.log(x)
 
-def exp_(x, base):
+def _exp(x, base):
     if base == 10:
         return np.power(10, x)
     return np.exp(x)