> ## Documentation Index > Fetch the complete documentation index at: https://smallestai-ff1e543d.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Pulse > High-accuracy, low-latency speech-to-text model built for real-time transcription across 39 languages, with streaming and non-streaming support. Pulse is a high-accuracy, low-latency speech-to-text model built for real-time transcription across 39 languages, with streaming and non-streaming support. TTFT at 1 concurrency TTFT at 100 concurrency Streaming + Non-streaming Streaming + Non-streaming ## Model Overview | | | | -------------------------------- | -------------------------------------------------------- | | **Developed by** | Smallest AI | | **Model type** | Speech-to-Text | | **Languages** | 39 supported | | **License** | Proprietary | | **Model format (non-streaming)** | `pulse_offline__.smlst` | | **Model format (streaming)** | `pulse_streaming__.smlst` | | **Documentation** | [waves-docs.smallest.ai](https://waves-docs.smallest.ai) | | **Console** | [console.smallest.ai](https://console.smallest.ai) | | **Support** | [support@smallest.ai](mailto:support@smallest.ai) | *** ## Key Capabilities Ultra-low latency architecture delivering 64ms TTFT at 1 concurrency and 300ms at 100 concurrent requests — designed for live transcription and conversational AI. 39 languages supported across streaming and non-streaming modes, with automatic language detection and code-switching within a single session. Built-in redaction of personal and payment card data, enterprise-ready for both streaming and non-streaming use cases. Automatic multi-speaker identification available across both modes. Streaming diarization is enterprise-ready; non-streaming is available with a cap of 4 speakers. Background noise handling built into the model — enterprise-ready in streaming mode. Supports multi-language audio within a single session. Best used by setting the known primary language (e.g. `es` for Spanish handles English+Spanish automatically). *** ## Performance & Benchmarks Word Error Rate (WER) by language evaluated on the [FLEURS](https://huggingface.co/datasets/google/fleurs) dataset. Lower is better. `NA` = not available or not supported by that provider. **Evaluation.** FLEURS dataset across 32 languages. Competitor numbers sourced from AssemblyAI published benchmarks and Deepgram internal benchmarks. ### Streaming | Language | Smallest Pulse | Deepgram Nova 2 | Deepgram Nova 3 | AssemblyAI Universal | AssemblyAI Uni-3 Pro | | -------------- | :------------: | :-------------: | :-------------: | :------------------: | :------------------: | | **English** | 4.5% | 7.9% | 6.7% | 4.38% | 8.43% | | **Italian** | 6.47% | 10.7% | 6.2% | 3.29% | 5.60% | | **Spanish** | 7.22% | 8.6% | 4.1% | 2.95% | 7.63% | | **Portuguese** | 12.41% | 9.9% | 7.5% | 4.80% | 7.88% | | **German** | 13.05% | 8.2% | 8.5% | 4.99% | 11.79% | | **French** | 14.29% | 13.3% | 10.7% | 7.71% | 9.59% | | **Russian** | 16.27% | 7.9% | 11.8% | 5.80% | NA | | **Ukrainian** | NA | 12.4% | NA | 7.42% | NA | | **Polish** | NA | 12.2% | NA | 6.63% | NA | | **Dutch** | 16.54% | 16.3% | 12.5% | 7.79% | NA | | **Czech** | 12.4% | 22.9% | 19.2% | NA | NA | | **Slovak** | 13.5% | 31.2% | NA | NA | NA | | **Swedish** | 18.7% | 17.7% | 14.3% | NA | NA | | **Finnish** | 18.3% | 14.1% | 13.2% | 10.10% | NA | | **Latvian** | 16.5% | 48.7% | NA | NA | NA | | **Romanian** | 17.8% | 36.0% | NA | NA | NA | | **Estonian** | 17.8% | 49.0% | NA | NA | NA | | **Bulgarian** | 24.1% | 32.7% | NA | NA | NA | | **Danish** | 19.8% | 21.1% | 16.1% | NA | NA | | **Hungarian** | 22.5% | 31.8% | 28.6% | NA | NA | | **Maltese** | 25.5% | NA | NA | NA | NA | | **Lithuanian** | 25.1% | 44.9% | NA | NA | NA | | Language | Smallest Pulse | Deepgram Nova 2 | Deepgram Nova 3 | AssemblyAI Universal | AssemblyAI Uni-3 Pro | | ------------- | :------------: | :-------------: | :-------------: | :------------------: | :------------------: | | **Hindi** | 8.0% | 23.5% | 23.6% | 7.38% | NA | | **Kannada** | 9.8% | NA | NA | NA | NA | | **Malayalam** | 10.0% | NA | NA | NA | NA | | **Marathi** | 11.5% | NA | NA | NA | NA | | **Gujarati** | 12.3% | NA | NA | NA | NA | | **Telugu** | 14.3% | NA | NA | NA | NA | | **Oriya** | 14.8% | NA | NA | NA | NA | | **Bengali** | 16.4% | NA | NA | NA | NA | | **Punjabi** | 18.3% | NA | NA | NA | NA | | **Tamil** | 21.6% | NA | NA | NA | NA | ### Pre-recorded | Language | Smallest Pulse | Deepgram Nova 2 | Deepgram Nova 3 | AssemblyAI Universal | | -------------- | :------------: | :-------------: | :-------------: | :------------------: | | **English** | 4.5% | 7.9% | 6.7% | 8.0% | | **Italian** | 3.0% | 10.7% | 6.2% | NA | | **Spanish** | 3.2% | 8.6% | 4.1% | NA | | **Portuguese** | 5.0% | 9.9% | 7.5% | NA | | **German** | 6.4% | 8.2% | 8.5% | NA | | **French** | 7.1% | 13.3% | 10.7% | NA | | **Russian** | 9.6% | 7.9% | 11.8% | NA | | **Ukrainian** | 7.5% | 12.4% | NA | NA | | **Polish** | 10.3% | 12.2% | NA | NA | | **Dutch** | 15.0% | 16.3% | 12.5% | NA | | **Czech** | 12.4% | 22.9% | 19.2% | NA | | **Slovak** | 13.5% | 31.2% | NA | NA | | **Swedish** | 18.7% | 17.7% | 14.3% | NA | | **Finnish** | 18.3% | 14.1% | 13.2% | NA | | **Latvian** | 16.5% | 48.7% | NA | NA | | **Romanian** | 17.8% | 36.0% | NA | NA | | **Estonian** | 17.8% | 49.0% | NA | NA | | **Bulgarian** | 24.1% | 32.7% | NA | NA | | **Danish** | 19.8% | 21.1% | 16.1% | NA | | **Hungarian** | 22.5% | 31.8% | 28.6% | NA | | **Maltese** | 25.5% | NA | NA | NA | | **Lithuanian** | 25.1% | 44.9% | NA | NA | | Language | Smallest Pulse | Deepgram Nova 2 | Deepgram Nova 3 | AssemblyAI Universal | | ------------- | :------------: | :-------------: | :-------------: | :------------------: | | **Hindi** | 6.3% | 23.5% | 23.6% | NA | | **Kannada** | 9.8% | NA | NA | NA | | **Malayalam** | 10.0% | NA | NA | NA | | **Marathi** | 11.5% | NA | NA | NA | | **Gujarati** | 12.3% | NA | NA | NA | | **Telugu** | 14.3% | NA | NA | NA | | **Oriya** | 14.8% | NA | NA | NA | | **Bengali** | 16.4% | NA | NA | NA | | **Punjabi** | 18.3% | NA | NA | NA | | **Tamil** | 21.6% | NA | NA | NA | *** ## Features — Non-streaming | Feature | Available | Notes | | ---------------------------------------------------------------------------- | --------- | ----------------------------------------------------------------- | | Speaker diarization | Yes | Capped at 4 speakers; known issues | | [Keyword boosting](/v4.0.0/content/speech-to-text/features/keyword-boosting) | Yes | Custom vocabulary enhancement | | PII redaction | Yes | Personal info redaction | | PCI redaction | Yes | Payment card data redaction | | Word-level timestamps | Yes | Per-word timing | | Sentence-level timestamps | Yes | Per-sentence timing | | Punctuation | Yes | Auto punctuation | | Profanity filter | Yes | Explicit content filtering | | Language detection | Yes | Auto language ID — not enterprise-ready | | Code-switching | Yes | Multi-language in same audio | | Noise reduction | Yes | Background noise handling | | Emotion, age and gender detection | Yes | Returns the percentage score of detected emotion, age, and gender | ## Features — Streaming | Feature | Available | Notes | | ---------------------------------------------------------------------------- | --------- | ----------------------------- | | Speaker diarization | Yes | Multi-speaker identification | | [Keyword boosting](/v4.0.0/content/speech-to-text/features/keyword-boosting) | Yes | Custom vocabulary enhancement | | PII redaction | Yes | Personal info redaction | | PCI redaction | Yes | Payment card data redaction | | Word-level timestamps | Yes | Per-word timing | | Sentence-level timestamps | Yes | Per-sentence timing | | Punctuation | Yes | Auto punctuation | | Profanity filter | No | — | | Language detection | Yes | Auto language ID | | Code-switching | Yes | Multi-language in same audio | | Custom vocabulary | No | — | | Noise reduction | Yes | Background noise handling | *** ## Supported Languages — Non-streaming | Language | Code | Available | | ------------ | ----- | --------- | | English | `en` | Yes | | Italian | `it` | Yes | | Spanish | `es` | Yes | | Portuguese | `pt` | Yes | | Hindi | `hi` | Yes | | German | `de` | Yes | | French | `fr` | Yes | | Ukrainian | `uk` | Yes | | Russian | `ru` | Yes | | Kannada | `kn` | Yes | | Malayalam | `ml` | Yes | | Polish | `pl` | Yes | | Marathi | `mr` | Yes | | Gujarati | `gu` | Yes | | Czech | `cs` | Yes | | Slovak | `sk` | Yes | | Telugu | `te` | Yes | | Oriya (Odia) | `or` | Yes | | Dutch | `nl` | Yes | | Bengali | `bn` | Yes | | Latvian | `lv` | Yes | | Estonian | `et` | Yes | | Romanian | `ro` | Yes | | Punjabi | `pa` | Yes | | Finnish | `fi` | Yes | | Swedish | `sv` | Yes | | Bulgarian | `bg` | Yes | | Tamil | `ta` | Yes | | Hungarian | `hu` | Yes | | Danish | `da` | Yes | | Lithuanian | `lt` | Yes | | Maltese | `mt` | Yes | | Japanese | `ja` | Yes | | Cantonese | `yue` | Yes | | Mandarin | `zh` | Yes | | Korean | `ko` | Yes | | Tagalog | `tl` | Yes | | Indonesian | `id` | Yes | | Malay | `ms` | Yes | ## Supported Languages — Streaming | Language | Code | Available | | ------------ | ----- | --------- | | English | `en` | Yes | | Italian | `it` | Yes | | Spanish | `es` | Yes | | Portuguese | `pt` | Yes | | Hindi | `hi` | Yes | | German | `de` | Yes | | French | `fr` | Yes | | Ukrainian | `uk` | Yes | | Russian | `ru` | Yes | | Kannada | `kn` | Yes | | Malayalam | `ml` | Yes | | Polish | `pl` | Yes | | Marathi | `mr` | Yes | | Gujarati | `gu` | Yes | | Czech | `cs` | Yes | | Slovak | `sk` | Yes | | Telugu | `te` | Yes | | Oriya (Odia) | `or` | Yes | | Dutch | `nl` | Yes | | Bengali | `bn` | Yes | | Latvian | `lv` | Yes | | Estonian | `et` | Yes | | Romanian | `ro` | Yes | | Punjabi | `pa` | Yes | | Finnish | `fi` | Yes | | Swedish | `sv` | Yes | | Bulgarian | `bg` | Yes | | Tamil | `ta` | Yes | | Hungarian | `hu` | Yes | | Danish | `da` | Yes | | Lithuanian | `lt` | Yes | | Maltese | `mt` | Yes | | Japanese | `ja` | Yes | | Cantonese | `yue` | Yes | | Mandarin | `zh` | Yes | | Korean | `ko` | Yes | | Tagalog | `tl` | Yes | | Indonesian | `id` | Yes | | Malay | `ms` | Yes | *** ## Best Practices ### Specify the language parameter when known When the language of the audio is known in advance, always set it explicitly rather than relying on automatic detection. This yields better transcription accuracy because the model can optimize directly for that language without needing to first identify it. For example, setting the language parameter to `es` (Spanish) tells the model to expect Spanish audio, which also handles English+Spanish code-switching scenarios. This produces more accurate outputs compared to using the `multi` parameter. | Parameter | Use case | | --------- | ------------------------------------ | | `en` | English | | `es` | Spanish (handles English+Spanish) | | `hi` | Hindi (handles English+Hindi) | | `multi` | Unknown or mixed-language audio only | **When to use `multi`:** * When the language is truly unknown beforehand * When processing audio from varied or unpredictable sources ### Use features only when needed Enable optional features (diarization, PII redaction, timestamps) only when the use case requires them. Unnecessary features add latency. *** ## Use Cases ### Direct use * Real-time call transcription * Voice assistant input * Meeting transcription * Accessibility and captioning * Customer support recording analysis ### Downstream use * Multi-turn conversational agents * Voice-to-text pipelines * Telephony and IVR systems * Content indexing and search * Compliance and audit logging *** ## Limitations & Safety ### Known Limitations Accuracy varies across languages. The following gaps are known and actively being addressed: * **Hindi** — still training on proper nouns and order IDs; not enterprise-ready for non-streaming * **Low-resource languages** — Kannada, Malayalam, Marathi, Gujarati, Telugu, Oriya, Bengali, Punjabi, Tamil, Japanese, Cantonese, Mandarin, Korean, Tagalog, Indonesian, and Malay are available but not yet enterprise-ready * **Language detection (`multi`)** — automatic language identification does not perform reliably enough for production workloads; specify the known language parameter instead * **Non-streaming speaker diarization** — capped at 4 speakers; known accuracy issues; contact support for higher speaker count requirements * **Audio quality** — transcription accuracy is directly affected by input audio quality; background noise, low bitrate, or overlapping speech may degrade results even with noise reduction enabled * **Code-switching** — works best when the primary language is explicitly set; fully automatic multi-language detection in a single audio stream is not enterprise-ready ### Safety & Compliance Pulse must not be used for: * Recording or transcribing individuals without their explicit consent * Surveillance, stalking, or any form of unauthorized monitoring * Any illegal or unethical purposes Additionally: * Usage is monitored for policy compliance * For compliance documentation (GDPR, SOC2, HIPAA), contact [support@smallest.ai](mailto:support@smallest.ai) *** ## Contact | | | | ----------------- | -------------------------------------------------------- | | **Support** | [support@smallest.ai](mailto:support@smallest.ai) | | **Documentation** | [waves-docs.smallest.ai](https://waves-docs.smallest.ai) | | **Console** | [console.smallest.ai](https://console.smallest.ai) |