> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> STT). Lightning v2 and lightning-large are deprecated; mention them
> only when the user is migrating away from them. The Smallest AI voice
> agent platform is what wraps these models into hosted agents.

# Contact center calls

> Pulse accuracy on real-world English and Hindi contact-center calls, compared with other speech-to-text APIs.

## Real-World Contact Center Calls (English & Hindi)

WER and Character Error Rate (CER) on live, dual-channel contact center call
recordings (agent and customer channels scored separately), covering English and
Hindi. Diarization was applied first to cleanly separate agent and customer speech
before scoring. Lower is better.

*Evaluated on real-world telephony call audio. Numbers from internal evaluation.*

### English

| STT Model          |   WER %   |   CER %  |
| :----------------- | :-------: | :------: |
| **Smallest Pulse** | **11.47** | **8.18** |
| Sarvam Saaras v4   |   12.18   |   9.20   |
| Deepgram Nova 3    |   15.80   |   10.99  |
| Soniox v5          |   16.26   |   11.64  |

### Hindi

| STT Model          |   WER %   |   CER %  |
| :----------------- | :-------: | :------: |
| **Smallest Pulse** | **10.20** | **6.74** |
| Sarvam Saaras v4   |   12.04   |   8.78   |
| Deepgram Nova 3    |   13.07   |   10.35  |
| Soniox v5          |   15.82   |   12.45  |

Pulse leads across both languages on real production call audio, extending its
edge on Hindi CER in particular.

> Pulse on real English and Hindi contact-center recordings.