diff --git a/TTS/utils/generic_utils.py b/TTS/utils/generic_utils.py
index 22287d14..140cf811 100644
--- a/TTS/utils/generic_utils.py
+++ b/TTS/utils/generic_utils.py
@@ -139,11 +139,11 @@ class KeepAverage:
             self.update_value(key, value)
 
 
-def check_argument(
-    name, c, enum_list=None, max_val=None, min_val=None, restricted=False, val_type=None, alternative=None
-):
+def check_argument(name, c, enum_list=None, max_val=None, min_val=None, restricted=False, alternative=None, allow_none=False):
     if alternative in c.keys() and c[alternative] is not None:
         return
+    if allow_none and c[name] is None:
+        return
     if restricted:
         assert name in c.keys(), f" [!] {name} not defined in config.json"
     if name in c.keys():
@@ -152,14 +152,4 @@ def check_argument(
         if min_val:
             assert c[name] >= min_val, f" [!] {name} is smaller than min value {min_val}"
         if enum_list:
-            assert c[name].lower() in enum_list, f" [!] {name} is not a valid value"
-        if isinstance(val_type, list):
-            is_valid = False
-            for typ in val_type:
-                if isinstance(c[name], typ):
-                    is_valid = True
-            assert is_valid or c[name] is None, f" [!] {name} has wrong type - {type(c[name])} vs {val_type}"
-        elif val_type:
-            assert (
-                isinstance(c[name], val_type) or c[name] is None
-            ), f" [!] {name} has wrong type - {type(c[name])} vs {val_type}"
+            assert c[name].lower() in enum_list, f' [!] {name} is not a valid value'