Models · Speech to text

Fourier STT hears Hindi right.

On RinggAI’s public Hindi benchmark it made the fewest word errors of five.

See the benchmark

Word error rate

RinggAI Hindi benchmark · 10,000 utterances²

  1. Fourier STT 9.12%
  2. Ringg Parrot 9.72%
  3. ElevenLabs 11.11%
  4. Sarvam 12.83%
  5. Deepgram 15.79%

Lower is better

Why Fourier STT

It is made for the way India talks on the phone.

It hears Hindi, English, Gujarati, Tamil and Telugu, and the English mixed into them.

  1. 01

    Hindi as it is spoken

    Code-mixed Hindi and English, with names and numbers mid-sentence. Built for conversational, phone-line Hindi.

  2. 02

    Holds up on new voices

    On Lahaja, 132 speakers from 83 districts it never trained on: 11.63% WER, against 16.55% for the open Qwen3-ASR model.

  3. 03

    Made for phone calls

    Built for conversational, phone-line Hindi and Hinglish, and served on our own engine and GPUs in India.

Benchmark

We measured it on a public Hindi benchmark.

The same 10,000 utterances for every system, across six corpora.

  • 9.12%word error rate
  • 3.21%character error rate
  • 15.5 hof Hindi audio, six corpora
  • 0empty transcripts
Compare with
Normalised word error rate %, lower is better. Marked: lowest for each dataset.
DetailFourier STTRingg ParrotElevenLabsSarvamDeepgram
By dataset
CommonVoice · 1,727 utterances 12.78% 12.62%lowest 15.98% 16.68% 18.49%
FLEURS · 418 utterances 9.89% 10.36% 9.74%lowest 13.40% 15.65%
IndicTTS · 100 utterances 5.31% 5.21%lowest 10.57% 10.32% 8.65%
Kathbath · 1,929 utterances 7.99%lowest 9.46% 12.14% 13.32% 14.18%
Kathbath noisy · 1,929 utterances 9.47%lowest 10.84% 11.83% 14.49% 15.61%
MUCS · 3,897 utterances 8.24%lowest 8.41% 8.97% 10.50% 16.03%
All 10,000 utterances
Overall · 10,000 utterances 9.12%lowest 9.72% 11.11% 12.83% 15.79%

Normalised word error rate %, lower is better. Marked: lowest for each dataset. Normalised folds spellings that sound the same (अन्दर = अंदर, लिये = लिए), never grammar: है and हैं still count as different words. Vendor scores use the outputs bundled in the dataset; their model versions are Ringg’s.

Pricing

Transcription is priced by the hour of audio.

Send a recorded call and get a transcript back, billed once the job completes.

Speech to text

Fourier STT

₹18an hour of recorded audio³

  • Offline transcription (POST /v2/transcriptions) is charged per second of audio, once, when a job completes. Degraded and failed jobs are free.
  • Speaker-labelled transcript with a speaker id per voice · Recordings up to 2 hours · Shared endpoint · No contractual SLA.
Read the transcription guide
Endpoint
POST /v2/transcriptions, with the same sk_live_ key as the rest of the v2 API.
Languages
Hindi, English, Gujarati, Tamil and Telugu, and the English mixed into them. The benchmark on this page is Hindi.
Where it runs
On our own engine and GPUs in India.
In a call
Every Frequency agent listens with Fourier STT, inside the agent’s per-minute price.

Questions

Questions people ask about Fourier STT.

What is Fourier STT?

Our own speech-to-text model, built for conversational, phone-line Hindi and Hinglish, and served on our own engine.

How accurate is it?

On all 10,000 utterances of RinggAI’s public Hindi benchmark, Fourier STT scored 9.12% word error rate, the lowest of the five systems scored. Ringg Parrot scored 9.72%.

Which languages does it support?

Hindi, English, Gujarati, Tamil and Telugu, including English words mixed into them. The benchmark on this page is Hindi only. Bengali, Marathi and Kannada follow as each clears our own evaluation.

Does it work on phone calls?

It is built for phone-line audio and runs inside our voice agents today. The benchmark on this page is public read and prompted speech, not phone calls, so we do not quote a phone-call accuracy figure from it.

How do I get access?

Try it inside a voice agent in the sandbox today. For recorded calls, the transcription API (POST /v2/transcriptions) takes recordings of up to 2 hours and bills by the hour of audio. For live audio, book a call and tell us what your callers sound like.

Still deciding? Ask us.

Fifteen minutes with the team that builds it. Bring your script, or your hardest call.

Book 15 minutes

Book a call

15 minutes with Sneh Mehta

Finding a time for us…

  1. AI agents from ₹1 a minute: on our volume plan, ₹1,00,000 a month. Pay as you go is ₹5 a minute. Prices exclude GST.

  2. RinggAI’s public Hindi benchmark (RinggAI/ASR-Benchmarking-Dataset), scored 23 September 2026, normalised word error rate. The benchmark is Hindi only, and it is read and prompted speech, not phone calls.

  3. Models are priced on their own, by the hour of audio, never by the minute of a call. Monthly commitments are credited to your wallet. Unused credit never expires. All prices exclude GST.