Audio annotation · বাংলা
Bengali Audio Annotation
Labelling of existing audio: speaker diarisation, emotion, intent, events, language identification and segment-level quality tagging, against your label schema. This page covers how that works specifically for Bengali, where inherent vowel is realised as /ɔ/ or /o/, which breaks g2p rules copied from devanagari-based systems.
- Language
- Bengali (bn-IN)
- Dialects covered
- 5
- Typical programme
- 500-2,000 hours
- Cities
- Kolkata, Siliguri, Durgapur
What changes when the language is Bengali
The service specification stays constant across languages; the linguistics do not. For Bengali, three things drive the design of a audio annotation programme.
- Inherent vowel is realised as /ɔ/ or /o/, which breaks G2P rules copied from Devanagari-based systems
- Dialect spread: Kolkata standard (Rarhi), Sylheti-influenced, Rangpuri / North Bengal, Medinipuri
- Kolkata professional speech mixes English heavily; rural West Bengal much less. A single 'Bengali' dataset without register tags conflates two very different acoustic and lexical distributions.
Technical specification
| Parameter | Standard |
|---|---|
| Label types | Diarisation, emotion, intent, events, language ID, quality |
| Granularity | Segment, utterance, or frame-level boundaries |
| Schema | Yours, or authored with you before work starts |
| Agreement | Multi-annotator overlap on a defined percentage |
| Tooling | Client tooling supported; otherwise our annotation workflow |
Bengali cohort design
Tag every speaker as Indian Bengali and record district of origin; mixing in Bangladeshi speech without tags is a common and costly dataset defect.
| Dimension | Typical split | Why it matters for Bengali |
|---|---|---|
| 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 Bengali forms that younger urban speakers have lost |
| Region | West Bengal / Tripura / Assam (Barak Valley) 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 |
Process
- Schema definition and edge-case documentation
- Annotator training and gold-set calibration
- Production annotation with gold items seeded in
- Adjudication of disagreements by a senior reviewer
- Delivery with per-label agreement statistics
Bengali-specific quality rules
- Three sibilant characters chosen inconsistently for the same sound
- Bangladeshi vs Indian Bengali orthographic conventions mixed within one dataset
- Verb conjugation register (cholit vs sadhu) normalised by transcribers
Gold items are seeded throughout production so drift is caught during the run, not at delivery.
Deliverables
- Labelled data in your schema
- Gold set and calibration results
- Per-label agreement statistics
- Edge-case log
Worked example
A representative Bengali audio annotation engagement: 500 hours from 1,000 speakers, 50/50 gender, ages 18-45, spread across Kolkata, Siliguri, Durgapur, recorded to the specification above and delivered in WAV with a per-utterance manifest.
Timeline: Scoped per label complexity; simple diarisation runs at roughly 3-5x real time.
Where this data is missing today
Indian Bengali is under-collected relative to Bangladeshi Bengali, and North Bengal and Tripura varieties are almost entirely missing.
Frequently asked
How much does Bengali audio annotation cost?
Priced per delivered hour or unit against a written spec. The cost drivers for Bengali are dialect spread, demographic narrowness and recording condition, in that order.
Which Bengali dialects are included?
By default Kolkata standard (Rarhi), Sylheti-influenced, Rangpuri / North Bengal, Medinipuri and others, tagged per speaker. You can also commission a single-dialect corpus if you are targeting one region.
Can you deliver Bengali data in our format?
Yes. Labelled data in your schema is the default, but naming, schema and directory structure follow your pipeline.
How long does a Bengali programme take?
Scoped per label complexity; simple diarisation runs at roughly 3-5x real time.
Request a Bengali audio annotation quote
Hours, speakers, dialects, deadline. Send what you have.