Dataset specification · Domain scale
250 hours of Odia Telephony Speech
A domain scale build of 250 hours of Odia telephony speech. Fine-tuning a production model for a specific domain, accent range or deployment condition. Speech captured over a real telephony path — a genuine call through the network, not studio audio downsampled afterwards to imitate one.

- Volume
- 250 hours
- Scale
- Domain scale
- Per speaker
- 10–20 minutes of accepted audio per speaker
- Accepted yield
- 50–60% of recorded time is accepted
How Odia telephony speech is captured
Speech captured over a real telephony path — a genuine call through the network, not studio audio downsampled afterwards to imitate one.
Scenario-driven calls between a caller and an agent or IVR flow, each leg recorded separately, across a deliberate spread of handsets and network conditions.
Yield at this style: 50–60% of recorded time is accepted. Dropped calls, network artefacts beyond tolerance and unusable legs are discarded. Real network conditions are the point of the style and also its main cost.
The specification
| Field | Value |
|---|---|
| Language | Odia (or-IN, Odia) |
| Volume | 250 hours |
| Equivalent | 500 speakers at 30 minutes each, or 250 speakers at one hour each |
| Speech type | Telephony Speech |
| Per speaker | 10–20 minutes of accepted audio per speaker |
| Sample rate | 8 kHz narrowband, matching what a deployed contact-centre model actually receives |
| Codec | G.711 and AMR-NB captured explicitly, with the codec recorded per call in the manifest |
| Legs | Caller and agent recorded on separate legs, never as a mixed call recording |
| Network conditions | Handset type, network carrier and packet-loss events logged per call |
| Dialects | Cuttack-Bhubaneswar standard, Sambalpuri (Kosli), Ganjami, Baleswari |
| Transcription | Verbatim, native-speaker, second-pass reviewed |

Designing the call flows for Odia
- Call scenarios drawn from real contact-centre intents: balance enquiry, complaint, booking change, escalation
- IVR flows scripted with deliberate mis-entry and barge-in paths, since those are where deployed systems fail
- Handset spread specified up front — low-end Android, feature phone, landline — because handset variance is a real acoustic axis
- Background conditions varied on purpose: street, vehicle, indoor, since real callers are rarely in quiet rooms
- Built against Odia specifically: Retains a distinct retroflex ଳ and a full retroflex series
- Code-mixing handled explicitly rather than edited out — Urban Odia mixes Hindi and English; western Odisha mixes Chhattisgarhi and Sambalpuri forms.
Running a domain scale Odia build
Six to eight weeks. Beyond three cities the bottleneck moves from recruitment to transcription throughput, which is why the transcriber count rises faster than the engineer count.
Four to five batches on a fortnightly cadence, sequenced so the dialects you care about most land first.
Western Odisha recruitment requires local field partners; remote-only recruitment yields an all-coastal cohort.
| Parameter | At this volume |
|---|---|
| Cities | Three to four — Bhubaneswar, Cuttack, Sambalpur, Berhampur |
| Studios | Three to four rooms plus one mobile rig |
| Recruiters | Four coordinators under one programme lead |
| Speakers | ~500–600 |
| Sessions per day | 25–30 nationally |
| Team | 1 programme lead, 4 coordinators, 8 engineers, 14 transcribers, 2 QA leads |
Cohort design
At 250 hours quotas are enforced per dialect and reconciled fortnightly. Aggregate demographics are reported per batch so drift is visible while there is still time to correct it.
Recruitment must be stratified by handset and carrier as well as by dialect, which adds a screening axis the other styles do not have.
| Dimension | Typical split | Why it matters for Odia |
|---|---|---|
| Gender | 50 / 50 | Pitch range differences change acoustic model behaviour; unbalanced cohorts bias recognition |
| Age | 18-25: 30%, 26-40: 40%, 41-60: 30% | Older speakers retain conservative Odia forms that younger urban speakers have lost |
| Region | Odisha / parts of Jharkhand, West Bengal, Chhattisgarh and Andhra Pradesh and others | Dialect spread across 5 recognised varieties |
| Education | Mixed, including below-graduate | Prompt-reading fluency correlates with education and skews prosody |
| Condition | Studio / quiet room / field | Match the noise profile of your deployment |
Odia-specific considerations
- Retains a distinct retroflex ଳ and a full retroflex series
- Urban Odia mixes Hindi and English; western Odisha mixes Chhattisgarhi and Sambalpuri forms.
- Odia is one of the least-resourced major Indian languages. Sambalpuri and Ganjami are effectively absent from public data.
Quality gates for telephony speech
- Codec and sample rate verified per file, rejecting any studio audio that has been downsampled to fake a telephony path
- Echo and double-talk checked on both legs
- DTMF events verified against the call log
- Level normalisation applied per leg, since handset output levels vary far more than studio microphones do
- Sambalpuri normalised into coastal Odia
- Unicode confusables between Odia and Bengali characters when transcribers reuse tooling
100% technical QA, 15% content QA with stratified sampling across city, dialect and transcriber, so no single team's output goes unchecked.
What goes wrong on telephony speech sessions
- Studio audio downsampled to 8 kHz and passed off as telephony, which has none of the codec or packet-loss characteristics that matter
- Echo and double-talk that make the agent leg unusable
- Carrier and handset monoculture, producing a corpus that only represents one acoustic path
- Over-clean recordings from participants who move somewhere quiet to take the call, defeating the purpose
Risks at domain scale in Odia
Cost at this band is driven by: Transcription depth — verbatim with disfluencies costs materially more than clean-read transcription; Number of distinct dialect quotas rather than raw hours.
- Transcription becomes the critical path and stays there for the rest of the volume bands
- Coordinator turnover mid-build causes quota drift that is only visible in the final demographic report unless it is audited weekly
- Odia carries 5 recognised varieties across Odisha, parts of Jharkhand, West Bengal, Chhattisgarh and Andhra Pradesh, so the quota matrix is wider than the headline volume suggests
- Odia is one of the least-resourced major Indian languages. Sambalpuri and Ganjami are effectively absent from public data.
Deliverables
- WAV audio to your naming convention, with the per-file manifest
- Verbatim Odia transcripts with utterance-level timestamps
- Call metadata: duration, codec, handset class, carrier, packet-loss events
- Intent label per call and per turn
- DTMF and hold, transfer and barge-in events
- Agent and caller leg identifiers
- Per-speaker metadata: age band, gender, region, dialect, education band
- Consent records mapped to speaker IDs
- QA report with pass rates, rejection reasons and agreement statistics
- Speaker-disjoint train / dev / test splits on request
What this trains, and what it does not
- Contact-centre and IVR ASR
- Voice bots operating over the phone network
- Intent classification on narrowband audio
- Robustness to codec and packet loss
Narrowband telephony audio is the wrong input for TTS or any wideband model — the frequency content simply is not there. Use it for models that will be deployed on a phone line and nothing else.
Frequently asked
Is 250 hours of Odia enough?
Enough to shift word error rate meaningfully on a domain-specific deployment. For a general-purpose model in a low-resource language, still a starting layer.
Why telephony speech rather than another speech type?
Contact-centre and IVR ASR, Voice bots operating over the phone network, Intent classification on narrowband audio are what this style is the right input for. Narrowband telephony audio is the wrong input for TTS or any wideband model — the frequency content simply is not there. Use it for models that will be deployed on a phone line and nothing else.
How long does a domain scale Odia build take?
Six to eight weeks. Beyond three cities the bottleneck moves from recruitment to transcription throughput, which is why the transcriber count rises faster than the engineer count. Four to five batches on a fortnightly cadence, sequenced so the dialects you care about most land first.
What does 250 hours of Odia telephony speech cost?
Quoted per delivered hour against this specification. At this band the drivers are transcription depth — verbatim with disfluencies costs materially more than clean-read transcription and number of distinct dialect quotas rather than raw hours. Send the spec and you get one fixed figure.
How much QA is applied at this volume?
100% technical QA, 15% content QA with stratified sampling across city, dialect and transcriber, so no single team's output goes unchecked.
Quote this Odia dataset
250 hours, telephony speech, Odia — domain scale. Adjust anything and send it.