Voice evaluation · TTS Voice Building
AI Voice Evaluation for TTS Voice Building
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. Applied to tts voice building, the specification is driven by one thing: mos naturalness.

- Service
- Voice evaluation
- Use case
- TTS Voice Building
- Primary metric
- MOS naturalness
Required data profile
- 10-40 hours from one speaker, or multi-speaker sets
- Phonetically balanced scripts
- Session-consistent acoustics
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 |

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
Metrics this feeds
- MOS naturalness
- Pronunciation accuracy on loanwords and names
- Prosody stability across long utterances
Failure modes to design out
- Session drift between recording days
- Scripts that under-cover rare phonemes
- Uncleared voice-talent licensing
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
Frequently asked
Is voice evaluation the right service for tts voice building?
It covers 10-40 hours from one speaker, or multi-speaker sets. Most tts voice building programmes combine it with at least one other service; we will say so in the scope rather than selling one line item.
What languages are available?
All 14 languages in the network plus Indian English accent bands.
How is the evaluation set handled?
Collected first, from speakers disjoint from the training cohort, so improvement is measurable.
Scope voice evaluation for tts voice building
Send the metric you need to move.