diff --git a/egs/tokenizer/CODEC/local/backend_np.py b/egs/tokenizer/CODEC/local/backend_np.py
new file mode 100644
index 000000000..b52254665
--- /dev/null
+++ b/egs/tokenizer/CODEC/local/backend_np.py
@@ -0,0 +1,55 @@
+from io import BytesIO
+from pathlib import Path
+from typing import NamedTuple, Optional, Tuple, Union
+
+import numpy as np
+import torch
+from lhotse.audio.backend import AudioBackend, FileObject
+from lhotse.utils import Pathlike, Seconds
+
+
+class WujiEEGBackend(AudioBackend):
+    def read_audio(
+        self,
+        path_or_fd: Union[Pathlike, FileObject],
+        offset: Seconds = 0.0,
+        duration: Optional[Seconds] = None,
+        force_opus_sampling_rate: Optional[int] = None,
+    ) -> Tuple[np.ndarray, int]:
+        np_arr = np.load(path_or_fd)
+        sampling_rate = int(np_arr["fs"])
+        return np_arr["eeg"][offset * sampling_rate : (offset + duration) * sampling_rate], sampling_rate 
+
+    def is_applicable(self, path_or_fd: Union[Pathlike, FileObject]) -> bool:
+        return True
+
+    def supports_save(self) -> bool:
+        return False
+
+    def save_audio(
+        self,
+        dest: Union[str, Path, BytesIO],
+        src: Union[torch.Tensor, np.ndarray],
+        sampling_rate: int,
+        format: Optional[str] = None,
+        encoding: Optional[str] = None,
+    ) -> None:
+        raise NotImplementedError("Saving audio is not supported for the WujiEEGBackend.")
+
+    def supports_info(self) -> bool:
+        return True
+
+    def info(
+        self,
+        path_or_fd: Union[Pathlike, FileObject],
+    ):
+        np_arr = np.load(path_or_fd)
+        sampling_rate = int(np_arr["fs"])
+        return NamedTuple(
+            channels=1,
+            frames=np_arr["eeg"].shape[0] // sampling_rate,
+            samplerate=sampling_rate,
+            duration=np_arr["eeg"].shape[0] / sampling_rate,
+            video= None,
+        )
+
diff --git a/egs/tokenizer/CODEC/local/prepare_eeg_manifest.py b/egs/tokenizer/CODEC/local/prepare_eeg_manifest.py
new file mode 100644
index 000000000..76d8e378e
--- /dev/null
+++ b/egs/tokenizer/CODEC/local/prepare_eeg_manifest.py
@@ -0,0 +1,55 @@
+from pathlib import Path
+
+from backend_np import WujiEEGBackend
+from lhotse import CutSet, MonoCut, Recording, SupervisionSegment
+from lhotse.audio.backend import set_current_audio_backend
+from tqdm import tqdm
+
+set_current_audio_backend(WujiEEGBackend())
+
+SPLIT=Path("/nvme3/wyc/sleep-net-zero/index/sleep_staging/hsp_nsrr.csv")
+DATA_DIR=Path("/home/jinzengrui/proj/biofall/egs/tokenizer/CODEC/data/from_wyc")
+
+if __name__ == "__main__":
+    with open(SPLIT, "r") as f:
+        csv_lines = f.readlines()
+    csv_lines = csv_lines[1:]
+    train_cuts, val_cuts = [], []
+
+    for line in tqdm(csv_lines):
+        line = line.strip()
+        npz_path, sess_id, duration, split = line.split(",")
+        duration = float(duration)
+        npz_path = Path(npz_path)
+        npz_fname = npz_path.stem.split(".")[0]
+        audio = Recording.from_file(npz_path, recording_id=f"{sess_id}-{npz_fname}")
+        cut = MonoCut(
+            id=f"{sess_id}-{npz_fname}",
+            start=0.0,
+            duration=duration,
+            channel=0,
+            recording=audio,
+            supervisions=[
+                SupervisionSegment(
+                    id=f"{sess_id}-{npz_fname}",
+                    recording_id=f"{sess_id}-{npz_fname}",
+                    start=0.0,
+                    duration=duration,
+                    channel=0,
+                    text="",
+                    language="",
+                    speaker=sess_id,
+                )
+            ],
+        )
+        if split == "train":
+            train_cuts.append(cut)
+        elif split == "val":
+            val_cuts.append(cut)
+        else:
+            raise ValueError(f"Unknown split: {split}")
+        
+    train_cuts = CutSet.from_cuts(cuts=train_cuts)
+    train_cuts.to_jsonl(DATA_DIR / "train.jsonl.gz")
+    val_cuts = CutSet.from_cuts(cuts=val_cuts)
+    val_cuts.to_jsonl(DATA_DIR / "val.jsonl.gz")
\ No newline at end of file