Voice evaluation · தமிழ்
Tamil 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 Tamil, where extreme diglossia: written tamil and spoken tamil differ so much that read-speech corpora are near-useless for conversational asr.
- Language
- Tamil (ta-IN)
- Dialects covered
- 6
- Typical programme
- 500-2,000 hours
- Cities
- Chennai, Coimbatore, Madurai
What changes when the language is Tamil
The service specification stays constant across languages; the linguistics do not. For Tamil, three things drive the design of a voice evaluation programme.
- Extreme diglossia: written Tamil and spoken Tamil differ so much that read-speech corpora are near-useless for conversational ASR
- Dialect spread: Chennai (Madras Bashai), Kongu (Coimbatore), Madurai, Nellai (Tirunelveli)
- Tanglish is the default urban register. Technology, finance, and workplace vocabulary is largely English embedded in Tamil syntax.
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 |
Tamil cohort design
Recruit by district rather than by city alone; Chennai-only cohorts produce models that degrade sharply in the south and west of the state.
| Dimension | Typical split | Why it matters for Tamil |
|---|---|---|
| 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 Tamil forms that younger urban speakers have lost |
| Region | Tamil Nadu / Puducherry / parts of Karnataka and Kerala and others | Dialect spread across 6 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
Tamil-specific quality rules
- Transcribers normalising spoken Tamil into literary Tamil, destroying the acoustic-text alignment
- ழ / ள / ல confusion
- Inconsistent handling of English insertions: Tamil script transliteration vs Latin script must be fixed in the guide
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 Tamil voice evaluation engagement: 500 hours from 1,000 speakers, 50/50 gender, ages 18-45, spread across Chennai, Coimbatore, Madurai, 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
Almost all public Tamil audio is literary read speech from news or scripture. Genuine colloquial Tamil, especially southern and Kongu varieties, is the single biggest gap for anyone building Tamil voice products.
Frequently asked
How much does Tamil voice evaluation cost?
Priced per delivered hour or unit against a written spec. The cost drivers for Tamil are dialect spread, demographic narrowness and recording condition, in that order.
Which Tamil dialects are included?
By default Chennai (Madras Bashai), Kongu (Coimbatore), Madurai, Nellai (Tirunelveli) and others, tagged per speaker. You can also commission a single-dialect corpus if you are targeting one region.
Can you deliver Tamil 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 Tamil programme take?
1-3 weeks per evaluation round.
Request a Tamil voice evaluation quote
Hours, speakers, dialects, deadline. Send what you have.