diff --git a/egs/voxpopuli/ASR/README.md b/egs/voxpopuli/ASR/README.md
index 1db13cf29..92aa26464 100644
--- a/egs/voxpopuli/ASR/README.md
+++ b/egs/voxpopuli/ASR/README.md
@@ -1,6 +1,8 @@
 # Readme
 
-This recipe contains data preparation for the VoxPopuli dataset.
+This recipe contains data preparation for the
+[VoxPopuli](https://github.com/facebookresearch/voxpopuli) dataset
+[(pdf)](https://aclanthology.org/2021.acl-long.80.pdf).
 At the moment, without model training.
 
 
diff --git a/egs/voxpopuli/ASR/local/compute_fbank.py b/egs/voxpopuli/ASR/local/compute_fbank.py
index 800074848..b63e51f29 100755
--- a/egs/voxpopuli/ASR/local/compute_fbank.py
+++ b/egs/voxpopuli/ASR/local/compute_fbank.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # Copyright    2021  Xiaomi Corp.        (authors: Fangjun Kuang)
-#              2023  Brno University of Technology (authors: Karel Veselý)
+#              2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -36,23 +36,29 @@ located at: `{src_dir}/{prefix}_cuts_{dataset}_raw.jsonl.gz`.
 The generated fbank features are saved in `data/fbank/{prefix}-{dataset}_feats`
 and CutSet manifest stored in `data/fbank/{prefix}_cuts_{dataset}.jsonl.gz`.
 
-The number of workers is smaller than nunber of jobs
+Typically, the number of workers is smaller than number of jobs
 (see --num-jobs 100 --num-workers 25 in the example).
+And, the number of jobs should be at least the number of workers (it's checked).
 """
 
 import argparse
 import logging
 import multiprocessing
 import os
-
 from concurrent.futures import ProcessPoolExecutor
 from pathlib import Path
 
 import sentencepiece as spm
 import torch
 from filter_cuts import filter_cuts
-from lhotse import CutSet, Fbank, FbankConfig, LilcomChunkyWriter
-from lhotse import is_caching_enabled, set_caching_enabled
+from lhotse import (
+    CutSet,
+    Fbank,
+    FbankConfig,
+    LilcomChunkyWriter,
+    is_caching_enabled,
+    set_caching_enabled,
+)
 
 from icefall.utils import str2bool
 
@@ -128,7 +134,6 @@ def get_args():
 
 
 def compute_fbank_features(args: argparse.Namespace):
-
     set_caching_enabled(True)  # lhotse
 
     src_dir = Path(args.src_dir)
@@ -181,6 +186,7 @@ def compute_fbank_features(args: argparse.Namespace):
     # We typically use `num_jobs=100, num_workers=20`
     # - this is helpful for large databases
     # - both values are configurable externally
+    assert num_jobs >= num_workers, (num_jobs, num_workers)
     executor = ProcessPoolExecutor(
         max_workers=num_workers,
         mp_context=multiprocessing.get_context("spawn"),
@@ -202,7 +208,7 @@ def compute_fbank_features(args: argparse.Namespace):
 
     # correct small deviations of duration, caused by speed-perturbation
     for cut in cut_set:
-        assert len(cut.supervisions) == 1
+        assert len(cut.supervisions) == 1, (len(cut.supervisions), cut.id)
         duration_difference = abs(cut.supervisions[0].duration - cut.duration)
         tolerance = 0.02  # 20ms
         if duration_difference == 0.0:
@@ -211,7 +217,7 @@ def compute_fbank_features(args: argparse.Namespace):
             logging.info(
                 "small mismatch of the supervision duration "
                 f"(Δt = {duration_difference*1000}ms), "
-                f"corretcing : cut.duration {cut.duration} -> "
+                f"correcting : cut.duration {cut.duration} -> "
                 f"supervision {cut.supervisions[0].duration}"
             )
             cut.supervisions[0].duration = cut.duration
diff --git a/egs/voxpopuli/ASR/local/display_manifest_statistics.py b/egs/voxpopuli/ASR/local/display_manifest_statistics.py
index 98c9825d3..36c99e126 100755
--- a/egs/voxpopuli/ASR/local/display_manifest_statistics.py
+++ b/egs/voxpopuli/ASR/local/display_manifest_statistics.py
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # Copyright    2021  Xiaomi Corp.        (authors: Fangjun Kuang)
-#              2023  Brno University of Technology (authors: Karel Veselý)
+#              2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
diff --git a/egs/voxpopuli/ASR/local/duration_from_supervision_manifest.py b/egs/voxpopuli/ASR/local/duration_from_supervision_manifest.py
index 0e6dc9512..957267fe8 100755
--- a/egs/voxpopuli/ASR/local/duration_from_supervision_manifest.py
+++ b/egs/voxpopuli/ASR/local/duration_from_supervision_manifest.py
@@ -1,5 +1,5 @@
-#!/bin/env python3
-# Copyright    2023  Brno University of Technology (authors: Karel Veselý)
+#!/usr/bin/env python3
+# Copyright    2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -25,11 +25,11 @@ Usage example:
 """
 
 import argparse
+import gzip
 import json
 import logging
-import sys
-import gzip
 import re
+import sys
 
 
 def get_args():
@@ -54,7 +54,6 @@ def main():
     total_n_utts = 0
 
     for fname in args.filename:
-
         if fname == "-":
             fd = sys.stdin
         elif re.match(r".*\.jsonl\.gz$", fname):
diff --git a/egs/voxpopuli/ASR/local/preprocess_voxpopuli.py b/egs/voxpopuli/ASR/local/preprocess_voxpopuli.py
index 39e80bf68..4032537db 100755
--- a/egs/voxpopuli/ASR/local/preprocess_voxpopuli.py
+++ b/egs/voxpopuli/ASR/local/preprocess_voxpopuli.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 # Copyright    2023  Xiaomi Corp.        (authors: Yifan Yang)
+#              2023  Brno University of Technology  (author: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -19,8 +20,8 @@
 Preprocess the database.
 - Convert RecordingSet and SupervisionSet to CutSet.
 - Apply text normalization to the transcripts.
-   - We take renormzlized `orig_text` as `text` transcripts.
-   - The the text normalization is separating punctuation from words.
+   - We take renormalized `orig_text` as `text` transcripts.
+   - The text normalization is separating punctuation from words.
    - Also we put capital letter to the beginning of a sentence.
 
 The script is inspired in:
@@ -40,12 +41,12 @@ from typing import Optional
 from lhotse import CutSet
 from lhotse.recipes.utils import read_manifests_if_cached
 
-from icefall.utils import str2bool
-
 # from local/
 from separate_punctuation import separate_punctuation
 from uppercase_begin_of_sentence import UpperCaseBeginOfSentence
 
+from icefall.utils import str2bool
+
 
 def get_args():
     parser = argparse.ArgumentParser()
diff --git a/egs/voxpopuli/ASR/local/separate_punctuation.py b/egs/voxpopuli/ASR/local/separate_punctuation.py
index decdf1de7..706d6fcd5 100755
--- a/egs/voxpopuli/ASR/local/separate_punctuation.py
+++ b/egs/voxpopuli/ASR/local/separate_punctuation.py
@@ -1,5 +1,5 @@
-#!/bin/env python3
-# Copyright    2023  Brno University of Technology (authors: Karel Veselý)
+#!/usr/bin/env python3
+# Copyright    2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -20,7 +20,7 @@ Example:
     input: "This is fine. Yes, you are right."
     output: "This is fine . Yes , you are right ."
 
-The script also handles exceptions in a hard-coded fasion.
+The script also handles exceptions in a hard-coded fashion.
 
 (same functionality could be done with `nltk.tokenize.word_tokenize()`,
  but that would be an extra dependency)
@@ -28,17 +28,18 @@ The script also handles exceptions in a hard-coded fasion.
 It can be used as a module, or as an executable script.
 
 Usage example #1:
-  from separate_punctuation import separate_punctuation
+  `from separate_punctuation import separate_punctuation`
 
 Usage example #2:
+```
   python3 ./local/separate_punctuation.py \
-    --ignore-columnts 1 \
-    ${kaldi_data}/text
+    --ignore-columns 1 \
+    < ${kaldi_data}/text
+```
 """
 
-import sys
 import re
-
+import sys
 from argparse import ArgumentParser
 
 
@@ -67,10 +68,8 @@ def separate_punctuation(text: str) -> str:
 
     # re-join the special cases of punctuation
     for ii, tok in enumerate(tokens):
-
         # no rewriting for 1st and last token
         if ii > 0 and ii < len(tokens) - 1:
-
             # **RULES ADDED FOR CZECH COMMON VOICE**
 
             # fix "27 . dubna" -> "27. dubna", but keep punctuation separate,
diff --git a/egs/voxpopuli/ASR/local/text_from_manifest.py b/egs/voxpopuli/ASR/local/text_from_manifest.py
index d02ecb6be..d9ab53b5a 100755
--- a/egs/voxpopuli/ASR/local/text_from_manifest.py
+++ b/egs/voxpopuli/ASR/local/text_from_manifest.py
@@ -1,5 +1,5 @@
-#!/bin/env python3
-# Copyright    2023  Brno University of Technology (authors: Karel Veselý)
+#!/usr/bin/env python3
+# Copyright    2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -15,7 +15,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-Print the text contained in `supervisions.jsonl.gz`.
+Print the text contained in `supervisions.jsonl.gz` or `cuts.jsonl.gz`.
 
 Usage example:
     python3 ./local/text_from_manifest.py \
@@ -23,8 +23,8 @@ Usage example:
 """
 
 import argparse
-import json
 import gzip
+import json
 
 
 def get_args():
@@ -41,7 +41,13 @@ def main():
     with gzip.open(args.filename, mode="r") as fd:
         for line in fd:
             js = json.loads(line)
-            print(js["text"])
+            if "text" in js:
+                print(js["text"])  # supervisions.jsonl.gz
+            elif "supervisions" in js:
+                for s in js["supervisions"]:
+                    print(s["text"])  # cuts.jsonl.gz
+            else:
+                raise Exception(f"Unknown jsonl format of {args.filename}")
 
 
 if __name__ == "__main__":
diff --git a/egs/voxpopuli/ASR/local/uppercase_begin_of_sentence.py b/egs/voxpopuli/ASR/local/uppercase_begin_of_sentence.py
index baa2e89c3..8e9de905f 100755
--- a/egs/voxpopuli/ASR/local/uppercase_begin_of_sentence.py
+++ b/egs/voxpopuli/ASR/local/uppercase_begin_of_sentence.py
@@ -1,5 +1,5 @@
-#!/bin/env python3
-# Copyright    2023  Brno University of Technology (authors: Karel Veselý)
+#!/usr/bin/env python3
+# Copyright    2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -19,17 +19,18 @@ This script introduces initial capital letter at the beginning of a sentence.
 It can be used as a module, or as an executable script.
 
 Usage example #1:
-  from uppercase_begin_of_sentence import UpperCaseBeginOfSentence
+  `from uppercase_begin_of_sentence import UpperCaseBeginOfSentence`
 
 Usage example #2:
+```
   python3 ./local/uppercase_begin_of_sentence.py \
-    --ignore-columnts 1 \
-    ${kaldi_data}/text
+    --ignore-columns 1 \
+    < ${kaldi_data}/text
+```
 """
 
 import re
 import sys
-
 from argparse import ArgumentParser
 
 
@@ -44,7 +45,6 @@ class UpperCaseBeginOfSentence:
     """
 
     def __init__(self):
-
         # The 1st word will have Title-case
         # This variable transfers context from previous line
         self.prev_token_is_punct = True
@@ -59,7 +59,6 @@ class UpperCaseBeginOfSentence:
         punct_set = set([".", "!", "?"])
 
         for ii, w in enumerate(words):
-
             # punctuation ?
             if w in punct_set:
                 self.prev_token_is_punct = True
diff --git a/egs/voxpopuli/ASR/local/validate_cutset_manifest.py b/egs/voxpopuli/ASR/local/validate_cutset_manifest.py
index ced4dcc98..4659aa9cd 100755
--- a/egs/voxpopuli/ASR/local/validate_cutset_manifest.py
+++ b/egs/voxpopuli/ASR/local/validate_cutset_manifest.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 # Copyright    2022  Xiaomi Corp.        (authors: Fangjun Kuang)
+#              2023  Brno University of Technology  (authors: Karel Veselý)
 #
 # See ../../../../LICENSE for clarification regarding multiple authors
 #
@@ -18,7 +19,8 @@
 This script checks the following assumptions of the generated manifest:
 
 - Single supervision per cut
-- Supervision time bounds are within cut time bounds
+- Supervision time bounds are within Cut time bounds
+- Duration of Cut and Superivion are equal
 
 We will add more checks later if needed.
 
@@ -27,14 +29,13 @@ Usage example:
     python3 ./local/validate_manifest.py \
             ./data/fbank/librispeech_cuts_train-clean-100.jsonl.gz
 
+(Based on: `librispeech/ASR/local/validate_manifest.py`)
 """
 
 import argparse
 import logging
 from pathlib import Path
 
-from icefall.utils import setup_logger
-
 from lhotse import CutSet, load_manifest_lazy
 from lhotse.cut import Cut
 from lhotse.dataset.speech_recognition import validate_for_asr
@@ -49,14 +50,6 @@ def get_args():
         help="Path to the manifest file",
     )
 
-    parser.add_argument(
-        "--log-file",
-        type=str,
-        default=None,
-        required=True,
-        help="The filename to save the log.",
-    )
-
     return parser.parse_args()
 
 
@@ -101,8 +94,6 @@ def main():
     args = get_args()
 
     manifest = args.cutset_manifest
-
-    setup_logger(log_filename=f"{args.log_file}", log_level="info")
     logging.info(f"Validating {manifest}")
 
     assert manifest.is_file(), f"{manifest} does not exist"
@@ -125,4 +116,8 @@ def main():
 
 
 if __name__ == "__main__":
+    formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+
     main()
diff --git a/egs/voxpopuli/ASR/prepare.sh b/egs/voxpopuli/ASR/prepare.sh
index 007dbec13..7cddad756 100755
--- a/egs/voxpopuli/ASR/prepare.sh
+++ b/egs/voxpopuli/ASR/prepare.sh
@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 
-. /mnt/matylda5/iveselyk/ASR_TOOLKITS/K2_SHERPA_PYTORCH20/conda-activate.sh
+# fix segmentation fault reported in https://github.com/k2-fsa/icefall/issues/674
+export PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
 
 set -euxo pipefail
 
@@ -8,28 +9,17 @@ nj=20
 stage=-1
 stop_stage=100
 
-# Split data/${lang}set to this number of pieces
-# This is to avoid OOM during feature extraction.
-num_splits=100
-
 # We assume dl_dir (download dir) contains the following
 # directories and files. If not, they will be downloaded
 # by this script automatically.
 #
-# [TODO update this]
+#  - $dl_dir/voxpopuli/raw_audios/$lang/$year
+#      This directory contains *.ogg files with audio downloaded and extracted from archives:
+#       https://dl.fbaipublicfiles.com/voxpopuli/audios/${lang}_${year}.tar
 #
-#  - $dl_dir/$release/$lang
-#      This directory contains the following files downloaded from
-#       https://mozilla-common-voice-datasets.s3.dualstack.us-west-2.amazonaws.com/${release}/${release}-${lang}.tar.gz
-#
-#     - clips
-#     - dev.tsv
-#     - invalidated.tsv
-#     - other.tsv
-#     - reported.tsv
-#     - test.tsv
-#     - train.tsv
-#     - validated.tsv
+#  - Note: the voxpopuli transcripts are downloaded to a ${tmp} folder
+#    as part of `lhotse prepare voxpopuli` from:
+#       https://dl.fbaipublicfiles.com/voxpopuli/annotations/asr/asr_${lang}.tsv.gz
 #
 #  - $dl_dir/musan
 #      This directory contains the following directories downloaded from
@@ -39,19 +29,19 @@ num_splits=100
 #     - noise
 #     - speech
 
-#dl_dir=$PWD/download
-dl_dir=/mnt/matylda6/szoke/EU-ASR/DATA
+dl_dir=$PWD/download
+#dl_dir=/mnt/matylda6/szoke/EU-ASR/DATA  # BUT
 
-#musan_dir=${dl_dir}/musan
-musan_dir=/mnt/matylda2/data/MUSAN
+musan_dir=${dl_dir}/musan
+#musan_dir=/mnt/matylda2/data/MUSAN  # BUT
 
-# Choose vlues from:
+# Choose value from ASR_LANGUAGES:
 #
-# "en", "de", "fr", "es", "pl", "it", "ro", "hu", "cs", "nl", "fi", "hr",
-# "sk", "sl", "et", "lt", "pt", "bg", "el", "lv", "mt", "sv", "da",
-# "asr", "10k", "100k", "400k"
+# [ "en", "de", "fr", "es", "pl", "it", "ro", "hu", "cs", "nl", "fi", "hr",
+# "sk", "sl", "et", "lt" ]
 #
-# See: https://github.com/lhotse-speech/lhotse/blob/c5f26afd100885b86e4244eeb33ca1986f3fa923/lhotse/bin/modes/recipes/voxpopuli.py#L77
+# See ASR_LANGUAGES in:
+# https://github.com/lhotse-speech/lhotse/blob/c5f26afd100885b86e4244eeb33ca1986f3fa923/lhotse/recipes/voxpopuli.py#L54C4-L54C4
 lang=en
 
 task=asr
@@ -102,12 +92,6 @@ if [ $stage -le 0 ] && [ $stop_stage -ge 0 ]; then
   if [ ! -d $musan_dir/musan ]; then
     lhotse download musan $musan_dir
   fi
-
-  # pre-download the transcripts
-  DOWNLOAD_BASE_URL="https://dl.fbaipublicfiles.com/voxpopuli"
-  dir=data/manifests; mkdir -p ${dir}
-  wget --tries=10 --continue --progress=bar --directory-prefix=${dir} \
-    "${DOWNLOAD_BASE_URL}/annotations/asr/${task}_${lang}.tsv.gz"
 fi
 
 if [ $stage -le 1 ] && [ $stop_stage -ge 1 ]; then
@@ -115,7 +99,7 @@ if [ $stage -le 1 ] && [ $stop_stage -ge 1 ]; then
   # We assume that you have downloaded the VoxPopuli corpus
   # to $dl_dir/voxpopuli
   if [ ! -e data/manifests/.voxpopuli-${task}-${lang}.done ]; then
-    # Warning : it requires Internet connection (it downloads transcripts)
+    # Warning : it requires Internet connection (it downloads transcripts to ${tmpdir})
     lhotse prepare voxpopuli --task asr --lang $lang -j $nj $dl_dir/voxpopuli data/manifests
     touch data/manifests/.voxpopuli-${task}-${lang}.done
   fi
@@ -150,7 +134,7 @@ if [ $stage -le 4 ] && [ $stop_stage -ge 4 ]; then
   for dataset in "dev" "test"; do
     if [ ! -e data/fbank/.voxpopuli-${task}-${lang}-${dataset}.done ]; then
       ./local/compute_fbank.py --src-dir data/fbank --output-dir data/fbank \
-          --num-jobs 50 --num-workers 10 \
+          --num-jobs 50 --num-workers ${nj} \
           --prefix "voxpopuli-${task}-${lang}" \
           --dataset ${dataset} \
           --trim-to-supervisions True
@@ -160,10 +144,10 @@ if [ $stage -le 4 ] && [ $stop_stage -ge 4 ]; then
 fi
 
 if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
-  log "Stage 6: Compute fbank for train set of VoxPopuli"
+  log "Stage 5: Compute fbank for train set of VoxPopuli"
   if [ ! -e data/fbank/.voxpopuli-${task}-${lang}-train.done ]; then
     ./local/compute_fbank.py --src-dir data/fbank --output-dir data/fbank \
-        --num-jobs 100 --num-workers 25 \
+        --num-jobs 100 --num-workers ${nj} \
         --prefix "voxpopuli-${task}-${lang}" \
         --dataset train \
         --trim-to-supervisions True \
@@ -173,7 +157,17 @@ if [ $stage -le 5 ] && [ $stop_stage -ge 5 ]; then
 fi
 
 if [ $stage -le 6 ] && [ $stop_stage -ge 6 ]; then
-  log "Stage 6: Compute fbank for musan"
+  log "Stage 6: Validate fbank manifests for VoxPopuli"
+  for dataset in "dev" "test" "train"; do
+    mkdir -p data/fbank/log/
+    ./local/validate_cutset_manifest.py \
+      data/fbank/voxpopuli-asr-en_cuts_${dataset}.jsonl.gz \
+      2>&1 | tee data/fbank/log/validate_voxpopuli-asr-en_cuts_${dataset}.log
+  done
+fi
+
+if [ $stage -le 7 ] && [ $stop_stage -ge 7 ]; then
+  log "Stage 7: Compute fbank for musan"
   mkdir -p data/fbank
   if [ ! -e data/fbank/.musan.done ]; then
     ./local/compute_fbank_musan.py
@@ -181,8 +175,8 @@ if [ $stage -le 6 ] && [ $stop_stage -ge 6 ]; then
   fi
 fi
 
-if [ $stage -le 7 ] && [ $stop_stage -ge 7 ]; then
-  log "Stage 7: Prepare BPE based lang"
+if [ $stage -le 8 ] && [ $stop_stage -ge 8 ]; then
+  log "Stage 8: Prepare BPE based lang"
 
   for vocab_size in ${vocab_sizes[@]}; do
     lang_dir=data/lang_bpe_${vocab_size}_${lang}