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Dataset pipeline illustration

How was this benchmark built?

Real Ethio Telecom recordings can't be shared for privacy reasons β€” so we rebuilt a representative dataset from the ground up, in seven stages, with two rounds of expert-in-the-loop review.

30 hrs
Audio recorded
7
Audio conditions
2
Expert review rounds
50/50
Gender balance
Multi-turn
Dialogue format
1
🎧 Study real Ethio Telecom calls Analysis

We first listened to real customer–agent conversations from Ethio Telecom to catalogue the acoustic fingerprints of the channel: narrow bandwidth, 50 Hz mains hum, packet loss, AGC compression, and codec artifacts.

Why this matters. The real recordings couldn't be redistributed for privacy reasons, so we needed to reproduce their audio properties from scratch.
See the resulting signal conditions β†’
2
πŸ“„ Collect textual source material Text

Gathered internal Ethio Telecom documents β€” service manuals, customer-support FAQs, and agent-training material β€” to seed realistic domain vocabulary and typical customer scenarios.

Why this matters. Grounding the dataset in authentic operational documents keeps the language natural, domain-specific, and free of fabricated terminology.
3
πŸ’¬ Generate multi-turn conversations Text

Used the source documents to synthesize realistic multi-turn customer ↔ agent dialogues that follow the flow of real telecom support calls β€” greetings, problem statements, verification, resolution, closing.

Why this matters. Full conversations (not isolated sentences) exercise the kinds of turn-taking, interruptions, and topic shifts an ASR model must handle in production.
4
βœ… Expert review β€” round 1 (text) Human-in-loop

Ethio Telecom staff read every generated dialogue and gave feedback on realism, terminology, and correctness. We iterated on the text until domain experts confirmed the scripts sounded like calls they actually take.

Why this matters. This catches synthetic phrasing, unnatural politeness, or missing local context that a generic language model can easily invent.
5
πŸŽ™οΈ Record with a gender-balanced voice team Audio

Trained a 50/50 male/female voice-actor team to perform the dialogues in a conversational, un-scripted register β€” including hesitations, back-channels, and overlapping turns. Total 30 hours of speech collected.

Why this matters. Balanced gender data lets us measure and mitigate the gender-WER gap that most large ASR models exhibit.
See the gender-gap analysis β†’
6
πŸ”Š Expert review β€” round 2 (audio) Human-in-loop

Ethio Telecom workers listened to the recordings and verified that the audio conversations matched the tone, pacing, and behavior of real interactions. Any takes that felt stilted or off-domain were re-recorded.

Why this matters. Text-level realism doesn't guarantee audio-level realism. Two independent review rounds keep both modalities honest.
7
🌊 Apply telecom-channel augmentations Augmentation

The clean recordings are passed through seven controlled conditions that simulate the artifacts observed in step 1 β€” from Clean Studio all the way to Narrowband 2G + Packet Loss β€” producing the final benchmark splits used for evaluation.

Why this matters. Systematic augmentation lets us measure robustness: how much does each model degrade as we move from studio to a bad phone line?
See spectrograms of each condition β†’

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