diff --git a/egs/librispeech/ASR/pruned_transducer_stateless7/conformer.py b/egs/librispeech/ASR/pruned_transducer_stateless7/conformer.py
index 944e010e8..2cbb9c570 100644
--- a/egs/librispeech/ASR/pruned_transducer_stateless7/conformer.py
+++ b/egs/librispeech/ASR/pruned_transducer_stateless7/conformer.py
@@ -163,15 +163,10 @@ class Conformer(EncoderInterface):
         # self.encoder_unmasked_dim.
         feature_mask_dropout_prob = 0.15
 
-        # we only apply the random frame masking on 90% of sequences; we leave the remaining 10%
-        # un-masked so that the model has seen un-masked data.
-        sequence_mask_dropout_prob = 0.9
-
-        # frame_mask is 0 with probability `feature_mask_dropout_prob`
         # frame_mask1 shape: (num_frames1, batch_size, 1)
-        frame_mask1 = torch.logical_or(
-            torch.rand(num_frames1, batch_size, 1, device=x.device) > feature_mask_dropout_prob,
-            torch.rand(1, batch_size, 1, device=x.device) > sequence_mask_dropout_prob).to(x.dtype)
+        frame_mask1 = (torch.rand(num_frames1, batch_size, 1, device=x.device) >
+                       feature_mask_dropout_prob).to(x.dtype)
+
 
         feature_mask1 = torch.ones(num_frames1, batch_size, self.d_model[1],
                                    dtype=x.dtype, device=x.device)