Voice evaluation · বাংলা
Bengali AI Voice Evaluation
Human evaluation of your speech models: MOS and preference testing for TTS, WER-in-context review for ASR, and native-speaker judgement on naturalness and intelligibility. 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 voice evaluation 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 |
|---|---|
| TTS | MOS (1-5), MUSHRA, and A/B preference protocols |
| ASR | Error typing: substitution, deletion, insertion, code-switch failure |
| Panel | Native speakers of the target variety, screened and calibrated |
| Sample size | Powered per the effect size you need to detect |
| Reporting | Per-item scores plus aggregate with confidence intervals |
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
- Protocol design and sample-size calculation
- Panel recruitment and calibration on reference items
- Blind evaluation with attention checks
- Statistical analysis
- Report with per-error-type breakdown
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
Attention checks and reference anchors are embedded so unreliable raters are detected and excluded before analysis.
Deliverables
- Raw per-rater scores
- Aggregated results with confidence intervals
- Error-type analysis
- Recommended fix priorities
Worked example
A representative Bengali voice evaluation 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: 1-3 weeks per evaluation round.
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 voice evaluation 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. Raw per-rater scores is the default, but naming, schema and directory structure follow your pipeline.
How long does a Bengali programme take?
1-3 weeks per evaluation round.
Request a Bengali voice evaluation quote
Hours, speakers, dialects, deadline. Send what you have.