Changelog

As previously announced, we will be sunsetting Claude 3.5 Sonnet and 3.7 Sonnet for LeMUR on October 29th. After this date, requests made using Claude 3.5 and 3.7 Sonnet will return errors.

If you are using this model, we recommend switching to Claude 4 Sonnet, which is more performant than Claude 3.5 and 3.7 Sonnet. You can switch models by setting the final_model parameter to anthropic/claude-sonnet-4-20250514

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Introducing new tools and model updates to help you build, deploy, and scale Voice AI applications:

Speech Understanding: Advanced speaker identification, custom formatting rules, and translation let you transform raw transcripts into structured data instantly

LLM Gateway: One API for your entire voice-to-intelligence pipeline with integrated access to GPT, Claude, Gemini, and others.

Voice AI Guardrails: PII redaction in 50+ languages, profanity filtering, and content moderation.

Model Enhancements:

• Automatically code-switch between 99 languages, with 64% fewer speaker counting errors
• Up to 57% accuracy improvements on critical terms with 1,000-word context-aware prompting

Read more about these tools in our blog and check out our documentation for more information.

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We've shipped significant improvements to speaker count accuracy on Universal and Slam-1:

• 36% more accurate speaker detection for pre-recorded files
• Fewer false positives and missed speakers - the model now consistently identifies the correct number of participants

Fix released to address hallucinations occasionally produced in Slam-1 transcriptions.

Slam-1 Timestamps:

• Fixed issue where sentences separated by silence were sometimes incorrectly combined due to inaccurate timestamps.
• Fix released to reduce occasional timestamp inconsistencies.

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We've released updates to our Universal-Streaming model, bringing significant performance improvements across the board.

‍What's better:

• Overall accuracy: 3% improvement in general transcription accuracy
  
• Accented speech: 4% better recognition for speakers with accents
  
• Conversation Intelligence segments: 4% improvement in conversation intelligence use cases
  
• Proper nouns: 7% better at recognizing names, brands, and places
  
• Repeated words: 21% improvement when speakers repeat themselves
  
• Speed: 20ms faster response time for even lower latency
  
• Keyterms Prompting: Up to 66% better recognition of your custom terms

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The keyterms_prompt parameter can now be used with Universal for pre-recorded audio transcription, ensuring accurate recognition of product names, people, and industry terms. This feature is in Beta and only available for English files. For more information, please refer to our documentation.

PII Audio Redaction is now available for files processed via the EU endpoint.

PII Redaction now supports additional languages: Afrikaans, Bengali, and Thai.

Fixed issue where occasionally Slam-1 incorrectly inserted new lines in transcripts.

LeMUR Integration: LeMUR is now available via the Playground, enabling enhanced language understanding and processing capabilities

Account-Based Playground: The Playground is now attached to individual accounts, allowing users to track their transcription history

Speaker Diarization: Fixed occasional errors when using speaker diarization with non-English languages

Slam-1:

• Resolved errors caused by multiple consecutive punctuation symbols (e.g., '??' or '!!')
• Fixed timestamp adjustments that were causing shifts in word ordering
• Reduced hallucinations in transcript text output

Text Formatting: Released a fix that mitigates occasional punctuation and casing inconsistencies in transcriptions

Voice AI finally understands the words that matter most to your business - product names, people, industry terms - with perfect accuracy in real-time.

The impact:

• 21% better accuracy than leading alternatives
• 67% lower cost ($0.04/hour)
• No impact on streaming latency

Who wins: Restaurant ordering bots that never mishear menu items. Medical schedulers that get doctor names right. Meeting tools with searchable, accurate transcripts.

Include a maximum of 100 keyterms per session. For more information about this new feature and implementation, please refer to our blog and documentation.

Universal now delivers production-ready accuracy and features across 99 languages through a single, unified endpoint.

What's new:

• Expanded language detection – Automatically detects all 99 languages (up from 17)
•  Global speaker diarization – Identify speakers in 95 languages with precision
• Superior performance – Experience 2-3x faster processing for languages like Spanish, French, and German
• Customizable language detection – Set expected languages and fallback options tailored to your specific use case

Enable comprehensive language detection with just one parameter and no complex integration required. Check out our blog and documentation to explore Universal's capabilities.

Added Voice Activity Detection (VAD) to our endpointing model for more accurate detection of ongoing speech. Interruptions are reduced by nearly 100%, while still accurately predicting user end of turns. This feature is now natively integrated into the model and works automatically so no setup is required.

Fixed a bug where using Slam-1 with speaker diarization occasionally resulted in a server error.

Added a toggle on the dashboard under the Billing tab in the Account section to switch the view between US and EU rates.

Our Universal-Streaming model has been updated with improved accuracy features.

What's New:

• 52% improvement in handling repeated digits and tokens - The model now captures repetitions like "555-5555" or "yes, yes, confirmed" much more accurately (error rate reduced from 28.20% to 13.47%)

This enhancement delivers significant improvements for voice agents processing phone numbers, confirmation codes, and account numbers, with particular value for AI receptionists, drive-thru ordering systems, and customer support applications.

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As previously announced, we have sunset Claude 3 Sonnet for LeMUR on July 21st.

If you were using this model, we recommend switching to Claude 4 Sonnet, which is more performant than Claude 3. You can switch models via the final_model parameter in LeMUR requests.

Released an update to our speaker diarization model so that it performs better in telephony conversations.

Fixed a bug where the min_speakers_expected and max_speakers_expected parameters in speaker_options were not being properly applied when the audio file length was shorter than two minutes.

We've upgraded Universal with advanced text formatting specifically for Spanish and German:

• Spanish: Automatic inverted question marks (¿) and exclamation points (¡)
• German: Proper noun capitalization following grammar rules
• Both: Context-aware punctuation and natural number formatting
  

Native speakers now prefer Universal's formatting 62.2% of the time for Spanish and 54.5% for German. For more information about results and metrics, check out our blog.

PII Audio Redaction is now supported for all languages that support PII Text Redaction (previously, only English and Spanish were supported). Refer to our documentation to see all languages and their supported features.

Fixed an edge case issue that could sometimes result in overlapping timestamps in transcripts with formatted numbers.

Fixed an issue with the /sentences endpoint where sentences were being created at periods used in abbreviations like “Dr.” or “Mrs.”.

Fixed an issue where the min_speakers_expected value was sometimes not properly applied to the speaker_options parameter.

Implemented an enhanced hallucination filter that mitigates prompt injection issues with Slam-1.

Released new in-house speaker embedding model delivering significant improvements for challenging audio environments while maintaining performance on clean recordings. This enhanced model provides more accurate meeting transcripts, reliable call center analytics, and consistent speaker identification in conference rooms, remote meetings, and multi-speaker interviews.

Key Improvements

• Noisy & Far-Field Scenarios: Error rates dropped from 29.1% to 20.4% - a 30% improvement for challenging acoustic environments where traditional systems fail.
• Short Audio Segments: 43% improvement in very short segments (250ms) under noisy conditions - now accurately tracking single words and brief acknowledgments.
• Multi-Speaker Robustness: Complex audio with multiple speakers and background noise that previously collapsed to a single speaker is now accurately separated.

This model is automatically active for all customers and no action required to benefit from improved diarization accuracy. For more information about using speaker diarization, please refer to our documentation.

We're excited to announce that Claude 4 Sonnet and Claude 4 Opus are now available through our LeMUR endpoint.

Claude 4 Sonnet delivers enhanced reasoning and improved performance for everyday tasks while maintaining exceptional speed and cost-effectiveness. It's perfect for applications requiring reliable, intelligent responses across a wide range of use cases.

• API Parameter: final_model: "anthropic/claude-sonnet-4-20250514"‍
• Availability: US and EU regions‍
• Pricing: Same as Claude 3.7 Sonnet
  
  • Input: $0.003 per 1k tokens
  • Output: $0.015 per 1k tokens

Claude 4 Opus represents our most capable model yet, offering superior performance on complex reasoning tasks, advanced creative work, and sophisticated problem-solving. It excels at nuanced analysis, detailed research, and handling intricate multi-step workflows.

• API Parameter: final_model: "anthropic/claude-opus-4-20250514"‍
• Availability: US region only‍
• Pricing: Same as Claude 3 Opus
  
  • Input: $0.015 per 1k tokens
  • Output: $0.075 per 1k tokens

To use Claude 4, update the final_model parameter in existing LeMUR API calls. For more information and implementation guidance, check out our documentation.

Added an optional `speaker_options` parameter that allows the user to specify a range for the number of possible speakers in audio files. This enhancement provides greater flexibility for processing audio with varying speaker counts, particularly files that contain more than 10 speakers. Refer to our documentation for more information.

Slam-1 and LeMUR are now available through our EU API endpoint, providing complete data residency compliance for European customers.

Slam-1 in the EU delivers the same industry-leading speech recognition accuracy with complete EU data residency. Audio data remains within EU boundaries while maintaining the same advanced capabilities and seamless API integration.

LeMUR in the EU brings powerful audio intelligence to EU customers with GDPR compliance, including audio summarization, Q&A capabilities, action item extraction, and support for Claude 3 Haiku, Claude 3.5 Sonnet, and Claude 3.7 Sonnet models.

Check out our documentation for more information about the EU API endpoint as well as Slam-1 and LeMUR.

When requesting audio redaction, there is now an option that allows users to receive back audio files even if they do not contain any redacted audio. For more information, please consult our documentation.