On September 15, Google announced two new voice models, Gemini 3.8 Live and Gemini 3.8 Live Extended Thinking, targeting real-time Voice Agent applications. The Extended Thinking version scored 82.6 on Artificial Analysis’ Speech-to-Speech Quality Index, ranking first. Both models are available to developers through Gemini API and Google AI Studio, highlighting the ability to execute tasks during a conversation. The models can call APIs or tools in the background while continuing to output voice responses to users, without interrupting the conversation flow.
Positioning differences between the two Gemini 3.8 Live models
Gemini 3.8 Live Positioned as a speech-to-speech model prioritizing large-scale deployment and cost efficiency, it ranked second in user preference in the Speech Agent Arena. Core capabilities include:
- Asynchronous function callExecute API and tool calls in the background while continuously streaming voice responses to the user.
- Real-time visual context: Incorporate real-time visual input into the conversational context, enabling voice agents to understand what users “said” and “saw.”
- Alphanumeric precisionAccurately parse alphanumeric information such as confirmation codes, claim numbers, and technical specifications.
- Support for 97+ languagesAutomatically detects and switches languages during conversations, with no manual setup required.
Gemini 3.8 Live Extended Thinking It is designed for highly complex tasks and has deeper reasoning capabilities. It supports “configurable thinking,” can process multi-step reasoning in the background while using spoken cues (such as “Let me verify…”) to keep the conversation uninterrupted, and announces task progress in real time.
Gemini 3.8 Live benchmark scores
The benchmark data released by Google shows:
- Artificial Analysis Speech-to-Speech Quality Index: Extended Thinking takes first place with 82.6 points, while the standard version 3.8 Live comes in second.
- τ-Voice agent task completion rate: Extended Thinking reaches 68.6%
- Sierra τ-Voice-banking：35.1%
- Big Bench Audio reasoning capability：97.7%
- ServiceNow EVA-BenchAdvanced the Pareto Frontier in balancing accuracy and conversational quality.
In a blog post, Google DeepMind Principal Engineer Tom Ouyang said the two models deliver a “step change” over the previous Live models and offer a more streamlined alternative to cascaded architectures.
Gemini 3.5 Transcribe: Synchronized Integration of Speech-to-Text Models
Google has also integrated Gemini 3.5 Transcribe, launched last month, into the same developer toolkit. This speech-to-text model supports 85+ languages, with a word error rate (WER) of 4.0% in streaming mode and 2.6% in non-streaming mode.
Special features include:
- Automatic code-switchingLanguage switching within and between sentences is handled automatically, with no manual configuration required.
- Custom vocabulary preferenceAllows passing in a list of up to 1,000 technical terms to guide speech recognition to prioritize recognition of domain-specific vocabulary.
- Smart Transcription Mode: Automatically remove filler words, correct verbal slips, and output structured, directly readable transcript text.
3.5 Transcribe can also process audio files up to 1 hour long via the Interactions API, with support for structured timestamps and speaker labels.
Pricing and Partners
Pricing for the Gemini 3.8 Live series is $0.005 per minute for audio input (about NT$0.16) and $0.018 per minute for audio output (about NT$0.59), which converts to approximately $3 per million Tokens for input and $12 per million Tokens for output.
On the partner side, platforms such as Agora, Fishjam, LiveKit, LangChain, Pipecat, Vercel, and Vision Agents now support Live API, handling real-time media streaming infrastructure. Enterprise partners include Salesforce, ServiceNow, Genspark, and Lumeris.
Google also offers a complete voice toolkit, including Gemini 3.5 Live Translate (speech-to-speech translation for 70+ languages), Gemini 3.1 Flash TTS (speech generation), and Lyria 3.5 (music generation), all accessible through the Gemini API.
Source: KOCPC Chinese