Text-to-speech · voice · music · sound

TTS and audio evaluation by native speakers, in hours.

Measure what a spectrogram can't: does this voice sound natural, friendly, right for the language? Rapidata collects MOS-style ratings and pairwise preferences on your audio from native speakers of the target language.

01what we measure

Naturalness, MOS and preference, the way speech teams report them.

Use the protocol your speech team already reports, or run several side by side on the same clips.

  • Naturalness / MOSRate each clip on a 1–5 scale for naturalness or overall quality and average into a mean opinion score.
  • Pairwise preferenceWhich of two voices sounds more natural, more friendly or more like the reference speaker.
  • PronunciationNative speakers flag mispronounced words, wrong stress and unnatural prosody.
  • Audio RLHFFeed the same preferences back as reward data for speech, music and sound generation models.
02native speakers

Judged by people who speak the language.

A Japanese voice should be judged by Japanese speakers. With Rapidata you can filter raters by spoken language and country, so each locale of a multilingual TTS model is rated by its own native audience rather than by a generic English-speaking panel.

Audio & TTS evaluation FAQ

Can't find the answer you're looking for?Contact our support team at info@rapidata.ai!

Play each generated clip to native speakers of the target language and collect 1–5 naturalness ratings (a mean opinion score) or pairwise preferences against a baseline voice; Rapidata runs both through one API.

Rapidata can target raters by spoken language and country across 190+ countries, so most major languages and many regional ones can be rated by native speakers.

Our public text-to-audio benchmark collected about 32,000 human responses in under an hour.