Nova-3 Expands Speech-to-Text Support for Thai, Cantonese, Mandarin, and Indic Languages

Deepgram is continuing to expand Nova-3 language coverage across Asia-Pacific, bringing production-ready speech-to-text transcription to more languages, dialects, and regional speech patterns. Nova-3 now supports Thai, Cantonese Traditional, Mandarin Simplified, and Mandarin Traditional, while also delivering improved speech recognition accuracy for Bengali, Marathi, Tamil, and Telugu. We’ve also added Gujarati as a newly supported language on Nova-3.

These additions expand Nova-3 in regions shaped by tonal speech, multiple writing systems, regional pronunciation variation, and complex linguistic structures that have historically challenged traditional speech-to-text systems. Nova-3 continues to improve transcription quality in both batch and streaming use cases, while preserving the low latency and production-ready performance required for voice AI applications.

Thai Speech-to-Text (th, th-TH)

Thai is spoken in Thailand and widely used in customer support, commerce, media, and conversational applications throughout Southeast Asia. As a tonal language, meaning changes based on pitch contour and pronunciation, creating challenges for generalized speech recognition systems. Chinese Language Variants

Cantonese Traditional Speech-to-Text (zh-HK)

Cantonese is widely spoken throughout Hong Kong and by global Cantonese-speaking diaspora communities. Its extensive tonal variation, fast conversational pacing, colloquial expressions, and region-specific pronunciation patterns can be difficult for ASR systems to model accurately. Cantonese speech also frequently blends conversational shorthand and multilingual phrasing, particularly in customer support and real-time communication workflows.

Mandarin Simplified Speech-to-Text (zh, zh-CN, zh-Hans)

Mandarin Simplified is used in mainland China in customer support, commerce, media, and conversational AI applications. Supporting Mandarin Simplified requires speech recognition systems to handle tonal pronunciation, regional accent variation, and fast conversational speech across large-scale real-time and transcription workflows.

Mandarin Traditional (zh-TW, zh-Hant)

Mandarin Traditional is spoken throughout Taiwan, Hong Kong, and many overseas Chinese communities. Unlike Simplified Chinese, Traditional Chinese preserves the original, more complex character forms and is commonly used in regional media, education, government, finance, and enterprise communication. Mandarin Traditional has distinct written forms and regional usage patterns that can introduce complexity for speech recognition systems.

Thai, Cantonese Traditional, Mandarin Simplified, and Mandarin Traditional are now available on Nova-3, bringing improved transcription quality across both streaming and batch workflows compared to Nova-2.The following benchmark results show relative Word Error Rate (WER) reductions compared to Nova-2 across newly supported Thai and Chinese language variants.

• Thai streaming transcription achieves a 69.43% relative WER reduction compared to Nova-2
• Mandarin Simplified batch transcription achieves a 65.21% relative WER reduction compared to Nova-2
• Cantonese Traditional achieves a 24.82% relative WER reduction, while Mandarin Traditional achieves a 44.87% relative WER reduction across batch workflows

In addition to new Thai and Chinese language support, Nova-3 has improved speech recognition accuracy across several Indic languages that were released earlier this year.

• Bengali (bn)
• Marathi (mr)
• Tamil (ta)
• Telugu (te)

These updates improve transcription quality in both streaming and batch workflows, helping developers build more reliable voice applications across South Asia.

Indic languages span multiple language families, scripts, and phonetic structures, often with significant regional variation and conversational speech patterns. Improving recognition quality across these languages supports customer support, conversational AI, transcription, and analytics workflows operating across diverse regional speech environments.

We’ve also added new support for Gujarati (gu, gu-IN) on Nova-3, further expanding Indic language coverage across India and global Gujarati-speaking diaspora communities.

All languages included in this release are available through the same API developers already use today. You can use Nova-3 for both streaming and batch transcription workflows without retraining or custom configuration.

Switching to any supported language is as simple as updating the language parameter in your request:

curl --request POST \
  --header "Authorization: Token YOUR_DEEPGRAM_API_KEY" \
  --header "Content-Type: audio/wav" \
  --data-binary @youraudio.wav \
  "https://api.deepgram.com/v1/listen?model=nova-3&language=zh-HK"

Supported language codes:

• Thai: th, th-TH
• Cantonese Traditional: zh-HK
• Mandarin Simplified: zh, zh-CN, zh-Hans
• Mandarin Traditional: zh-TW, zh-Hant
• Bengali: bn
• Marathi: mr
• Tamil: ta
• Telugu: te
• Gujarati: gu, gu-IN

Sign up free and unlock $200 in credits, enough to power over 750 hours of transcription or 200 hours of speech-to-text across Nova-3’s growing language suite. Explore details on our Models & Languages Overview page and experience Nova-3’s world-class adaptability for yourself.