diff --git a/egs/aidatatang_200zh/ASR/local/compute_fbank_aidatatang_200zh.py b/egs/aidatatang_200zh/ASR/local/compute_fbank_aidatatang_200zh.py
index 387c14acf..9caacb78b 100755
--- a/egs/aidatatang_200zh/ASR/local/compute_fbank_aidatatang_200zh.py
+++ b/egs/aidatatang_200zh/ASR/local/compute_fbank_aidatatang_200zh.py
@@ -32,7 +32,7 @@ import torch
 from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import get_executor
+from icefall.utils import get_executor, str2bool
 
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
@@ -42,7 +42,7 @@ torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
 
 
-def compute_fbank_aidatatang_200zh(num_mel_bins: int = 80):
+def compute_fbank_aidatatang_200zh(num_mel_bins: int = 80, perturb_speed: bool = False):
     src_dir = Path("data/manifests/aidatatang_200zh")
     output_dir = Path("data/fbank")
     num_jobs = min(15, os.cpu_count())
@@ -85,7 +85,8 @@ def compute_fbank_aidatatang_200zh(num_mel_bins: int = 80):
                 recordings=m["recordings"],
                 supervisions=m["supervisions"],
             )
-            if "train" in partition:
+            if "train" in partition and perturb_speed:
+                logging.info(f"Doing speed perturb")
                 cut_set = (
                     cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
                 )
@@ -109,7 +110,12 @@ def get_args():
         default=80,
         help="""The number of mel bins for Fbank""",
     )
-
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
     return parser.parse_args()
 
 
@@ -119,4 +125,6 @@ if __name__ == "__main__":
     logging.basicConfig(format=formatter, level=logging.INFO)
 
     args = get_args()
-    compute_fbank_aidatatang_200zh(num_mel_bins=args.num_mel_bins)
+    compute_fbank_aidatatang_200zh(
+        num_mel_bins=args.num_mel_bins, perturb_speed=args.perturb_speed
+    )
diff --git a/egs/aidatatang_200zh/ASR/prepare.sh b/egs/aidatatang_200zh/ASR/prepare.sh
index 46ecd5769..2eb0b3718 100755
--- a/egs/aidatatang_200zh/ASR/prepare.sh
+++ b/egs/aidatatang_200zh/ASR/prepare.sh
@@ -77,7 +77,7 @@ if [ $stage -le 4 ] && [ $stop_stage -ge 4 ]; then
   log "Stage 4: Compute fbank for aidatatang_200zh"
   if [ ! -f data/fbank/.aidatatang_200zh.done ]; then
     mkdir -p data/fbank
-    ./local/compute_fbank_aidatatang_200zh.py
+    ./local/compute_fbank_aidatatang_200zh.py --perturb-speed True
     touch data/fbank/.aidatatang_200zh.done
   fi
 fi
diff --git a/egs/aishell/ASR/local/compute_fbank_aidatatang_200zh.py b/egs/aishell/ASR/local/compute_fbank_aidatatang_200zh.py
index 037971927..6a9bb4f42 100755
--- a/egs/aishell/ASR/local/compute_fbank_aidatatang_200zh.py
+++ b/egs/aishell/ASR/local/compute_fbank_aidatatang_200zh.py
@@ -32,7 +32,7 @@ import torch
 from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import get_executor
+from icefall.utils import get_executor, str2bool
 
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
@@ -42,7 +42,7 @@ torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
 
 
-def compute_fbank_aidatatang_200zh(num_mel_bins: int = 80):
+def compute_fbank_aidatatang_200zh(num_mel_bins: int = 80, perturb_speed: bool = False):
     src_dir = Path("data/manifests")
     output_dir = Path("data/fbank")
     num_jobs = min(15, os.cpu_count())
@@ -85,7 +85,8 @@ def compute_fbank_aidatatang_200zh(num_mel_bins: int = 80):
                 recordings=m["recordings"],
                 supervisions=m["supervisions"],
             )
-            if "train" in partition:
+            if "train" in partition and perturb_speed:
+                logging.info(f"Doing speed perturb")
                 cut_set = (
                     cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
                 )
@@ -109,7 +110,12 @@ def get_args():
         default=80,
         help="""The number of mel bins for Fbank""",
     )
-
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
     return parser.parse_args()
 
 
@@ -119,4 +125,6 @@ if __name__ == "__main__":
     logging.basicConfig(format=formatter, level=logging.INFO)
 
     args = get_args()
-    compute_fbank_aidatatang_200zh(num_mel_bins=args.num_mel_bins)
+    compute_fbank_aidatatang_200zh(
+        num_mel_bins=args.num_mel_bins, perturb_speed=args.perturb_speed
+    )
diff --git a/egs/aishell/ASR/local/compute_fbank_aishell.py b/egs/aishell/ASR/local/compute_fbank_aishell.py
index 115ca1031..c7000da1c 100755
--- a/egs/aishell/ASR/local/compute_fbank_aishell.py
+++ b/egs/aishell/ASR/local/compute_fbank_aishell.py
@@ -32,7 +32,7 @@ import torch
 from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import get_executor
+from icefall.utils import get_executor, str2bool
 
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
@@ -42,7 +42,7 @@ torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
 
 
-def compute_fbank_aishell(num_mel_bins: int = 80):
+def compute_fbank_aishell(num_mel_bins: int = 80, perturb_speed: bool = False):
     src_dir = Path("data/manifests")
     output_dir = Path("data/fbank")
     num_jobs = min(15, os.cpu_count())
@@ -81,7 +81,8 @@ def compute_fbank_aishell(num_mel_bins: int = 80):
                 recordings=m["recordings"],
                 supervisions=m["supervisions"],
             )
-            if "train" in partition:
+            if "train" in partition and perturb_speed:
+                logging.info(f"Doing speed perturb")
                 cut_set = (
                     cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
                 )
@@ -104,7 +105,12 @@ def get_args():
         default=80,
         help="""The number of mel bins for Fbank""",
     )
-
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
     return parser.parse_args()
 
 
@@ -114,4 +120,6 @@ if __name__ == "__main__":
     logging.basicConfig(format=formatter, level=logging.INFO)
 
     args = get_args()
-    compute_fbank_aishell(num_mel_bins=args.num_mel_bins)
+    compute_fbank_aishell(
+        num_mel_bins=args.num_mel_bins, perturb_speed=args.perturb_speed
+    )
diff --git a/egs/aishell/ASR/prepare.sh b/egs/aishell/ASR/prepare.sh
index b763d72c1..ff8e1301d 100755
--- a/egs/aishell/ASR/prepare.sh
+++ b/egs/aishell/ASR/prepare.sh
@@ -114,7 +114,7 @@ if [ $stage -le 3 ] && [ $stop_stage -ge 3 ]; then
   log "Stage 3: Compute fbank for aishell"
   if [ ! -f data/fbank/.aishell.done ]; then
     mkdir -p data/fbank
-    ./local/compute_fbank_aishell.py
+    ./local/compute_fbank_aishell.py --perturb-speed True
     touch data/fbank/.aishell.done
   fi
 fi
diff --git a/egs/aishell/ASR/prepare_aidatatang_200zh.sh b/egs/aishell/ASR/prepare_aidatatang_200zh.sh
index f1d4d18a7..ec89450df 100755
--- a/egs/aishell/ASR/prepare_aidatatang_200zh.sh
+++ b/egs/aishell/ASR/prepare_aidatatang_200zh.sh
@@ -53,7 +53,7 @@ if [ $stage -le 2 ] && [ $stop_stage -ge 2 ]; then
   log "Stage 2: Process aidatatang_200zh"
   if [ ! -f data/fbank/.aidatatang_200zh_fbank.done ]; then
     mkdir -p data/fbank
-    ./local/compute_fbank_aidatatang_200zh.py
+    ./local/compute_fbank_aidatatang_200zh.py --perturb-speed True
     touch data/fbank/.aidatatang_200zh_fbank.done
   fi
 fi
diff --git a/egs/aishell2/ASR/local/compute_fbank_aishell2.py b/egs/aishell2/ASR/local/compute_fbank_aishell2.py
index ec0c584ca..1fb1621ff 100755
--- a/egs/aishell2/ASR/local/compute_fbank_aishell2.py
+++ b/egs/aishell2/ASR/local/compute_fbank_aishell2.py
@@ -32,7 +32,7 @@ import torch
 from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import get_executor
+from icefall.utils import get_executor, str2bool
 
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
@@ -42,7 +42,7 @@ torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
 
 
-def compute_fbank_aishell2(num_mel_bins: int = 80):
+def compute_fbank_aishell2(num_mel_bins: int = 80, perturb_speed: bool = False):
     src_dir = Path("data/manifests")
     output_dir = Path("data/fbank")
     num_jobs = min(15, os.cpu_count())
@@ -81,7 +81,8 @@ def compute_fbank_aishell2(num_mel_bins: int = 80):
                 recordings=m["recordings"],
                 supervisions=m["supervisions"],
             )
-            if "train" in partition:
+            if "train" in partition and perturb_speed:
+                logging.info(f"Doing speed perturb")
                 cut_set = (
                     cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
                 )
@@ -104,6 +105,12 @@ def get_args():
         default=80,
         help="""The number of mel bins for Fbank""",
     )
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
 
     return parser.parse_args()
 
@@ -114,4 +121,6 @@ if __name__ == "__main__":
     logging.basicConfig(format=formatter, level=logging.INFO)
 
     args = get_args()
-    compute_fbank_aishell2(num_mel_bins=args.num_mel_bins)
+    compute_fbank_aishell2(
+        num_mel_bins=args.num_mel_bins, perturb_speed=args.perturb_speed
+    )
diff --git a/egs/aishell2/ASR/prepare.sh b/egs/aishell2/ASR/prepare.sh
index 3e8e840ab..42631c864 100755
--- a/egs/aishell2/ASR/prepare.sh
+++ b/egs/aishell2/ASR/prepare.sh
@@ -101,7 +101,7 @@ if [ $stage -le 3 ] && [ $stop_stage -ge 3 ]; then
   log "Stage 3: Compute fbank for aishell2"
   if [ ! -f data/fbank/.aishell2.done ]; then
     mkdir -p data/fbank
-    ./local/compute_fbank_aishell2.py
+    ./local/compute_fbank_aishell2.py --perturb-speed True
     touch data/fbank/.aishell2.done
   fi
 fi
diff --git a/egs/aishell4/ASR/local/compute_fbank_aishell4.py b/egs/aishell4/ASR/local/compute_fbank_aishell4.py
index 400c406f0..f19163988 100755
--- a/egs/aishell4/ASR/local/compute_fbank_aishell4.py
+++ b/egs/aishell4/ASR/local/compute_fbank_aishell4.py
@@ -32,7 +32,7 @@ import torch
 from lhotse import ChunkedLilcomHdf5Writer, CutSet, Fbank, FbankConfig
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import get_executor
+from icefall.utils import get_executor, str2bool
 
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
@@ -42,7 +42,7 @@ torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
 
 
-def compute_fbank_aishell4(num_mel_bins: int = 80):
+def compute_fbank_aishell4(num_mel_bins: int = 80, perturb_speed: bool = False):
     src_dir = Path("data/manifests/aishell4")
     output_dir = Path("data/fbank")
     num_jobs = min(15, os.cpu_count())
@@ -83,10 +83,12 @@ def compute_fbank_aishell4(num_mel_bins: int = 80):
                 recordings=m["recordings"],
                 supervisions=m["supervisions"],
             )
-            if "train" in partition:
+            if "train" in partition and perturb_speed:
+                logging.info(f"Doing speed perturb")
                 cut_set = (
                     cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
                 )
+
             cut_set = cut_set.compute_and_store_features(
                 extractor=extractor,
                 storage_path=f"{output_dir}/{prefix}_feats_{partition}",
@@ -113,6 +115,12 @@ def get_args():
         default=80,
         help="""The number of mel bins for Fbank""",
     )
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
 
     return parser.parse_args()
 
@@ -123,4 +131,6 @@ if __name__ == "__main__":
     logging.basicConfig(format=formatter, level=logging.INFO)
 
     args = get_args()
-    compute_fbank_aishell4(num_mel_bins=args.num_mel_bins)
+    compute_fbank_aishell4(
+        num_mel_bins=args.num_mel_bins, perturb_speed=args.perturb_speed
+    )
diff --git a/egs/aishell4/ASR/prepare.sh b/egs/aishell4/ASR/prepare.sh
index cb2b73a3e..1b1ec0005 100755
--- a/egs/aishell4/ASR/prepare.sh
+++ b/egs/aishell4/ASR/prepare.sh
@@ -107,7 +107,7 @@ if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
   log "Stage 5: Compute fbank for aishell4"
   if [ ! -f data/fbank/.aishell4.done ]; then
     mkdir -p data/fbank
-    ./local/compute_fbank_aishell4.py
+    ./local/compute_fbank_aishell4.py --perturb-speed True
     touch data/fbank/.aishell4.done
   fi
 fi
diff --git a/egs/alimeeting/ASR/local/compute_fbank_alimeeting.py b/egs/alimeeting/ASR/local/compute_fbank_alimeeting.py
index 96115a230..f8c10648a 100755
--- a/egs/alimeeting/ASR/local/compute_fbank_alimeeting.py
+++ b/egs/alimeeting/ASR/local/compute_fbank_alimeeting.py
@@ -32,7 +32,7 @@ import torch
 from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import get_executor
+from icefall.utils import get_executor, str2bool
 
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
@@ -42,7 +42,7 @@ torch.set_num_threads(1)
 torch.set_num_interop_threads(1)
 
 
-def compute_fbank_alimeeting(num_mel_bins: int = 80):
+def compute_fbank_alimeeting(num_mel_bins: int = 80, perturb_speed: bool = False):
     src_dir = Path("data/manifests/alimeeting")
     output_dir = Path("data/fbank")
     num_jobs = min(15, os.cpu_count())
@@ -82,7 +82,8 @@ def compute_fbank_alimeeting(num_mel_bins: int = 80):
                 recordings=m["recordings"],
                 supervisions=m["supervisions"],
             )
-            if "train" in partition:
+            if "train" in partition and perturb_speed:
+                logging.info(f"Doing speed perturb")
                 cut_set = (
                     cut_set + cut_set.perturb_speed(0.9) + cut_set.perturb_speed(1.1)
                 )
@@ -114,6 +115,12 @@ def get_args():
         default=80,
         help="""The number of mel bins for Fbank""",
     )
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
 
     return parser.parse_args()
 
@@ -124,4 +131,6 @@ if __name__ == "__main__":
     logging.basicConfig(format=formatter, level=logging.INFO)
 
     args = get_args()
-    compute_fbank_alimeeting(num_mel_bins=args.num_mel_bins)
+    compute_fbank_alimeeting(
+        num_mel_bins=args.num_mel_bins, perturb_speed=args.perturb_speed
+    )
diff --git a/egs/alimeeting/ASR/prepare.sh b/egs/alimeeting/ASR/prepare.sh
index 604cc92c6..1709733c7 100755
--- a/egs/alimeeting/ASR/prepare.sh
+++ b/egs/alimeeting/ASR/prepare.sh
@@ -97,7 +97,7 @@ if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
   log "Stage 5: Compute fbank for alimeeting"
   if [ ! -f data/fbank/.alimeeting.done ]; then
     mkdir -p data/fbank
-    ./local/compute_fbank_alimeeting.py
+    ./local/compute_fbank_alimeeting.py --perturb-speed True
     touch data/fbank/.alimeeting.done
   fi
 fi
diff --git a/egs/alimeeting/ASR_v2/local/compute_fbank_alimeeting.py b/egs/alimeeting/ASR_v2/local/compute_fbank_alimeeting.py
index c6aa2ab36..833d11c72 100755
--- a/egs/alimeeting/ASR_v2/local/compute_fbank_alimeeting.py
+++ b/egs/alimeeting/ASR_v2/local/compute_fbank_alimeeting.py
@@ -25,6 +25,7 @@ It looks for manifests in the directory data/manifests.
 
 The generated fbank features are saved in data/fbank.
 """
+import argparse
 import logging
 from pathlib import Path
 
@@ -39,6 +40,8 @@ from lhotse.features.kaldifeat import (
 )
 from lhotse.recipes.utils import read_manifests_if_cached
 
+from icefall.utils import str2bool
+
 # Torch's multithreaded behavior needs to be disabled or
 # it wastes a lot of CPU and slow things down.
 # Do this outside of main() in case it needs to take effect
@@ -48,7 +51,7 @@ torch.set_num_interop_threads(1)
 torch.multiprocessing.set_sharing_strategy("file_system")
 
 
-def compute_fbank_ami():
+def compute_fbank_ami(perturb_speed: bool = False):
     src_dir = Path("data/manifests")
     output_dir = Path("data/fbank")
 
@@ -84,8 +87,12 @@ def compute_fbank_ami():
         suffix="jsonl.gz",
     )
 
-    def _extract_feats(cuts: CutSet, storage_path: Path, manifest_path: Path) -> None:
-        cuts = cuts + cuts.perturb_speed(0.9) + cuts.perturb_speed(1.1)
+    def _extract_feats(
+        cuts: CutSet, storage_path: Path, manifest_path: Path, speed_perturb: bool
+    ) -> None:
+        if speed_perturb:
+            logging.info(f"Doing speed perturb")
+            cuts = cuts + cuts.perturb_speed(0.9) + cuts.perturb_speed(1.1)
         _ = cuts.compute_and_store_features_batch(
             extractor=extractor,
             storage_path=storage_path,
@@ -109,6 +116,7 @@ def compute_fbank_ami():
         cuts_ihm,
         output_dir / "feats_train_ihm",
         src_dir / "cuts_train_ihm.jsonl.gz",
+        perturb_speed,
     )
 
     logging.info("Processing train split IHM + reverberated IHM")
@@ -117,6 +125,7 @@ def compute_fbank_ami():
         cuts_ihm_rvb,
         output_dir / "feats_train_ihm_rvb",
         src_dir / "cuts_train_ihm_rvb.jsonl.gz",
+        perturb_speed,
     )
 
     logging.info("Processing train split SDM")
@@ -129,6 +138,7 @@ def compute_fbank_ami():
         cuts_sdm,
         output_dir / "feats_train_sdm",
         src_dir / "cuts_train_sdm.jsonl.gz",
+        perturb_speed,
     )
 
     logging.info("Processing train split GSS")
@@ -141,6 +151,7 @@ def compute_fbank_ami():
         cuts_gss,
         output_dir / "feats_train_gss",
         src_dir / "cuts_train_gss.jsonl.gz",
+        perturb_speed,
     )
 
     logging.info("Preparing test cuts: IHM, SDM, GSS (optional)")
@@ -186,8 +197,21 @@ def compute_fbank_ami():
         )
 
 
+def get_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
+    return parser.parse_args()
+
+
 if __name__ == "__main__":
     formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
     logging.basicConfig(format=formatter, level=logging.INFO)
 
-    compute_fbank_ami()
+    args = get_args()
+
+    compute_fbank_ami(perturb_speed=args.perturb_speed)
diff --git a/egs/alimeeting/ASR_v2/prepare.sh b/egs/alimeeting/ASR_v2/prepare.sh
index 76a108771..1098840f8 100755
--- a/egs/alimeeting/ASR_v2/prepare.sh
+++ b/egs/alimeeting/ASR_v2/prepare.sh
@@ -85,7 +85,7 @@ fi
 if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
   log "Stage 5: Compute fbank for alimeeting"
   mkdir -p data/fbank
-  python local/compute_fbank_alimeeting.py
+  python local/compute_fbank_alimeeting.py --perturb-speed True
   log "Combine features from train splits"
   lhotse combine data/manifests/cuts_train_{ihm,ihm_rvb,sdm,gss}.jsonl.gz - | shuf |\
     gzip -c > data/manifests/cuts_train_all.jsonl.gz
diff --git a/egs/wenetspeech/ASR/local/preprocess_wenetspeech.py b/egs/wenetspeech/ASR/local/preprocess_wenetspeech.py
index 93ce750f8..5de3c23a9 100755
--- a/egs/wenetspeech/ASR/local/preprocess_wenetspeech.py
+++ b/egs/wenetspeech/ASR/local/preprocess_wenetspeech.py
@@ -16,6 +16,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import argparse
 import logging
 import re
 from pathlib import Path
@@ -24,6 +25,7 @@ from lhotse import CutSet, SupervisionSegment
 from lhotse.recipes.utils import read_manifests_if_cached
 
 from icefall import setup_logger
+from icefall.utils import str2bool
 
 # Similar text filtering and normalization procedure as in:
 # https://github.com/SpeechColab/WenetSpeech/blob/main/toolkits/kaldi/wenetspeech_data_prep.sh
@@ -45,7 +47,7 @@ def has_no_oov(
     return oov_pattern.search(sup.text) is None
 
 
-def preprocess_wenet_speech():
+def preprocess_wenet_speech(perturb_speed: bool = False):
     src_dir = Path("data/manifests")
     output_dir = Path("data/fbank")
     output_dir.mkdir(exist_ok=True)
@@ -110,7 +112,7 @@ def preprocess_wenet_speech():
         )
         # Run data augmentation that needs to be done in the
         # time domain.
-        if partition not in ["DEV", "TEST_NET", "TEST_MEETING"]:
+        if partition not in ["DEV", "TEST_NET", "TEST_MEETING"] and perturb_speed:
             logging.info(
                 f"Speed perturb for {partition} with factors 0.9 and 1.1 "
                 "(Perturbing may take 8 minutes and saving may take 20 minutes)"
@@ -120,10 +122,22 @@ def preprocess_wenet_speech():
         cut_set.to_file(raw_cuts_path)
 
 
+def get_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--perturb-speed",
+        type=str2bool,
+        default=False,
+        help="Enable 0.9 and 1.1 speed perturbation for data augmentation. Default: False.",
+    )
+    return parser.parse_args()
+
+
 def main():
     setup_logger(log_filename="./log-preprocess-wenetspeech")
 
-    preprocess_wenet_speech()
+    args = get_args()
+    preprocess_wenet_speech(perturb_speed=args.perturb_speed)
     logging.info("Done")
 
 
diff --git a/egs/wenetspeech/ASR/prepare.sh b/egs/wenetspeech/ASR/prepare.sh
index f7b521794..097a59a5f 100755
--- a/egs/wenetspeech/ASR/prepare.sh
+++ b/egs/wenetspeech/ASR/prepare.sh
@@ -91,7 +91,7 @@ fi
 if [ $stage -le 3 ] && [ $stop_stage -ge 3 ]; then
   log "Stage 3: Preprocess WenetSpeech manifest"
   if [ ! -f data/fbank/.preprocess_complete ]; then
-    python3 ./local/preprocess_wenetspeech.py
+    python3 ./local/preprocess_wenetspeech.py --perturb-speed True
     touch data/fbank/.preprocess_complete
   fi
 fi