BrunoHays/apollo-telephony-en

Apollo telephony — English (processed)

English air-to-ground / mission-control telephony speech from the Apollo FSC P4 ASR track-2 corpus. Remastered for 8 kHz telephony ASR evaluation and training.

Credits & license

Original corpus: Apollo FSC P4 ASR track 2.
License: CC BY-4.0 (commercial use allowed with attribution).

Snapshot

• Language: en
• Samples: 48068 clips (~38.39 h)
• Audio: OGG/Opus mono, 8 kHz
• Splits: original Apollo partition — train (36320 / ~29.76 h), dev (11748 / ~8.63 h)
• License: CC-BY-4.0

What changed vs upstream

1. Audio remastered to OGG/Opus mono at native 8 kHz.
2. Light GT cleanup: [unk] → <unintelligible> (4810 rows). Caps, spelled numerals (ONE ZERO, NINER), and other Apollo orthography are unchanged.

original_transcription is the upstream text; transcription is the working reference (processed when set, else original).

Dataset structure

field	description
audio	OGG/Opus, 8 kHz mono
audio_id	e.g. …_track2_train_34911
license	CC-BY-4.0
original_transcription	upstream transcript
processed_transcription	cleaned text when changed, else empty
transcription	best available (= processed if set, else original)
dur / sample_rate / lang / split / src / channels	metadata

Notes

Spelled letters and numerals are intentional in this domain. High WER against modern ASR is often orthography / ITN, not wrong labels.