***

description: >-
Export processed audio data and transcriptions in formats optimized for ASR
training and multimodal applications
categories:

* data-export
  tags:
* output-formats
* manifests
* jsonl
* metadata
* asr-training
  personas:
* data-scientist-focused
* mle-focused
  difficulty: beginner
  content\_type: how-to
  modality: audio-only

***

# Save & Export Audio Data

Export processed audio data and transcriptions in formats optimized for ASR model training, audio-and-text applications, and downstream analysis workflows.

## Output Formats

NeMo Curator's audio curation pipeline supports several output formats tailored for different use cases:

### JSONL Manifests

The primary output format for audio curation is JSONL (JSON Lines):

```json
{"audio_filepath": "/data/audio/sample_001.wav", "text": "hello world", "pred_text": "hello world", "wer": 0.0, "duration": 2.1}
{"audio_filepath": "/data/audio/sample_002.wav", "text": "good morning", "pred_text": "good morning", "wer": 0.0, "duration": 1.8}
```

### Metadata Fields

Standard fields included in audio manifests:

| Field            | Type   | Description                    |
| ---------------- | ------ | ------------------------------ |
| `audio_filepath` | string | Absolute path to audio file    |
| `text`           | string | Ground truth transcription     |
| `pred_text`      | string | ASR model prediction           |
| `wer`            | float  | Word Error Rate percentage     |
| `duration`       | float  | Audio duration in seconds      |
| `language`       | string | Language identifier (optional) |

## Export Configuration

<Tabs>
  <Tab title="Using JsonlWriter">
    ```python
    from nemo_curator.stages.text.io.writer import JsonlWriter
    from nemo_curator.stages.audio.io.convert import AudioToDocumentStage

    # Convert AudioBatch to DocumentBatch for text writer
    pipeline.add_stage(AudioToDocumentStage())

    # Configure JSONL export
    pipeline.add_stage(
        JsonlWriter(
            path="/output/audio_manifests",
            write_kwargs={"force_ascii": False}  # Support Unicode characters
        )
    )
    ```
  </Tab>
</Tabs>

## Directory Structure

### Standard Output Layout

When `source_files` metadata exists, the writer generates deterministic hashed file names. Otherwise, it generates UUID-based names.

```text
/output/audio_manifests/
├── <hash>.jsonl   # Deterministic hash if metadata.source_files present, else UUID
├── <hash>.jsonl
└── ...
```

## Quality Control

### Validation Checks

Before export, check your processed data:

```python
from nemo_curator.stages.audio.common import PreserveByValueStage

# Filter by quality thresholds
quality_filters = [
    # Keep samples with WER &lt;= 50%
    PreserveByValueStage(
        input_value_key="wer",
        target_value=50.0,
        operator="le"
    ),
    # Keep samples with duration 1-30 seconds
    PreserveByValueStage(
        input_value_key="duration", 
        target_value=1.0,
        operator="ge"
    ),
    PreserveByValueStage(
        input_value_key="duration",
        target_value=30.0, 
        operator="le"
    )
]

for filter_stage in quality_filters:
    pipeline.add_stage(filter_stage)
```