diff --git a/i6_models/primitives/specaugment.py b/i6_models/primitives/specaugment.py
index 79272eaf..b4d4d761 100644
--- a/i6_models/primitives/specaugment.py
+++ b/i6_models/primitives/specaugment.py
@@ -51,12 +51,12 @@ def _random_mask(tensor: torch.Tensor, batch_axis: int, axis: int, min_num: int,
 
 def zero_specaugment(
     audio_features: torch.Tensor,
-    time_min_num_masks,
-    time_max_num_masks,
-    time_mask_max_size,
-    freq_min_num_masks,
-    freq_max_num_masks,
-    freq_mask_max_size,
+    time_min_num_masks: int,
+    time_max_num_masks: int,
+    time_mask_max_size: int,
+    freq_min_num_masks: int,
+    freq_max_num_masks: int,
+    freq_mask_max_size: int,
 ):
     """
     Specaugment from legacy rossenbach/zeineldeen/zeyer attention setups (usually called specaugment_v2.py or so),
@@ -74,19 +74,23 @@ def zero_specaugment(
     :return: masked audio features
     """
     assert len(tensor.shape) == 3
-    tensor = _random_mask(audio_features, 0, 1, 2, time_num_masks, time_mask_max_size)  # time masking
-    tensor = _random_mask(audio_features, 0, 2, 2, freq_num_masks, freq_mask_max_size)  # freq masking
+    tensor = _random_mask(
+        audio_features, 0, 1, time_min_num_masks, time_max_num_masks, time_mask_max_size
+    )  # time masking
+    tensor = _random_mask(
+        audio_features, 0, 2, freq_min_num_masks, freq_max_num_masks, freq_mask_max_size
+    )  # freq masking
     return tensor
 
 
 def zero_specaugment_by_length(
-    audio_features,
-    time_mask_per_n_frames,
-    time_min_num_masks,
-    time_mask_max_size,
-    freq_min_num_masks,
-    freq_max_num_masks,
-    freq_mask_max_size,
+    audio_features: torch.Tensor,
+    time_mask_per_n_frames: int,
+    time_min_num_masks: int,
+    time_mask_max_size: int,
+    freq_min_num_masks: int,
+    freq_max_num_masks: int,
+    freq_mask_max_size: int,
 ):
     """
     Convenience wrapper around zero_specaugment with time-length adaptive number of masks
@@ -103,10 +107,10 @@ def zero_specaugment_by_length(
     :param freq_mask_max_size: maximum size of masks along F
     :return: masked audio features
     """
-    return returnn_specaugment(
+    return zero_specaugment(
         audio_features,
-        time_num_masks=audio_features.size(1) // time_mask_per_n_frames,
         time_min_num_masks=time_min_num_masks,
+        time_max_num_masks=audio_features.size(1) // time_mask_per_n_frames,
         time_mask_max_size=time_mask_max_size,
         freq_min_num_masks=freq_min_num_masks,
         freq_max_num_masks=freq_max_num_masks,