Speech Data Explorer


The tool could be found under NeMo/tools/speech_data_explorer.

Dash-based tool for interactive exploration of ASR/TTS datasets.


  • dataset’s statistics (alphabet, vocabulary, duration-based histograms)

  • navigation across dataset (sorting, filtering)

  • inspection of individual utterances (waveform, spectrogram, audio player)

  • errors’ analysis (Word Error Rate, Character Error Rate, Word Match Rate, Mean Word Accuracy, diff)

Please make sure that requirements are installed. Then run:

python data_explorer.py path_to_manifest.json

JSON manifest file should contain the following fields:

  • audio_filepath (path to audio file)

  • duration (duration of the audio file in seconds)

  • text (reference transcript)

Errors’ analysis requires “pred_text” (ASR transcript) for all utterances.

Any additional field will be parsed and displayed in ‘Samples’ tab.