Interactive AI Avatars: Building Voice Agents with Azure Voice Live API
Azure Voice Live API recently reached General Availability, marking a significant milestone in conversational AI technology. This unified API surface doesn't just enable speech-to-speech capabilities for AI agents—it revolutionizes the entire experience by streaming interactions through lifelike avatars. Built on the powerful speech-to-speech capabilities of the GPT-4 Realtime model, Azure Voice Live API offers developers unprecedented flexibility: - Out-of-the-box or custom avatars from Azure AI Services - Wide range of neural voices, including Indic languages like the one featured in this demo - Single API interface that handles both audio processing and avatar streaming - Real-time responsiveness with sub-second latency In this post, I'll walk you through building a retail e-commerce voice agent that demonstrates this technology. While this implementation focuses on retail apparel, the architecture is entirely generic and can be adapted to any domain—healthcare, banking, education, or customer support—by simply changing the system prompt and implementing domain-specific tools integration. The Challenge: Navigating Uncharted Territory At the time of writing, documentation for implementing avatar features with Azure Voice Live API is minimal. The protocol-specific intricacies around avatar video streaming and the complex sequence of steps required to establish a live avatar connection were quite overwhelming. This is where Agent mode in GitHub Copilot in Visual Studio Code proved extremely useful. Through iterative conversations with the AI agent, I successfully discovered the approach to implement avatar streaming without getting lost in low-level protocol details. Here's how different AI models contributed to this solution: - Claude Sonnet 4.5: Rapidly architected the application structure, designing the hybrid WebSocket + WebRTC architecture with TypeScript/Vite frontend and FastAPI backend - GPT-5-Codex (Preview): Instrumental in implementing the complex avatar streaming components, handling WebRTC peer connections, and managing the bidirectional audio flow Architecture Overview: A Hybrid Approach The architecture comprises of these components 🐳 Container Application Architecture Vite Server: Node.js-based development server that serves the React application. In development, it provides hot module replacement and proxies API calls to `FastAPI`. In production, the React app is built into static files served by FastAPI. FastAPI with ASGI: Python web framework running on `uvicorn ASGI server`. ASGI (Asynchronous Server Gateway Interface) enables handling multiple concurrent connections efficiently, crucial for WebSocket connections and real-time audio processing. 🤖 AI & Voice Services Integration Azure Voice Live API: Primary service that manages the connection to GPT-4 Realtime Model, provides avatar video generation, neural text-to-speech, and WebSocket gateway functionality GPT-4 Realtime Model: Accessed through Azure Voice Live API for real-time audio processing, function calling, and intelligent conversation management 🔄 Communication Flows Audio Flow: Browser → WebSocket → FastAPI → WebSocket → Azure Voice Live API → GPT-4 Realtime Model Video Flow: Browser ↔ WebRTC Direct Connection ↔ Azure Voice Live API (bypasses backend for performance) Function Calls: GPT-4 Realtime (via Voice Live) → FastAPI Tools → Business APIs → Response → GPT-4 Realtime (via Voice Live) 🤖 Business process automation Workflows / RAG Shipment Logic App Agent: Analyzes orders, validates data, creates shipping labels, and updates tracking information Conversation Analysis Agent: Azure Logic App Reviews complete conversations, performs sentiment analysis, generates quality scores with justification, and stores insights for continuous improvement Knowledge Retrieval: Azure AI Search is used to reason over manuals and help respond to Customer queries on policies, products The solution implements a hybrid architecture that leverages both WebSocket proxying and direct WebRTC connections for optimal performance. This design ensures the conversational audio flow remains manageable and secure through the backend, while the bandwidth-intensive avatar video streams directly to the browser for optimal performance. The flow used in the Avatar communication: ``` Frontend FastAPI Backend Azure Voice Live API │ │ │ │ 1. Request Session │ │ │─────────────────────────►│ │ │ │ 2. Create Session │ │ │─────────────────────────►│ │ │ │ │ │ 3. Session Config │ │ │ (with avatar settings)│ │ │─────────────────────────►│ │ │ │ │ │ 4. session.updated │ │ │ (ICE servers) │ │ 5. ICE servers │◄─────────────────────────│ │◄─────────────────────────│ │ │ │ │ │ 6. Click "Start Avatar" │ │ │ │ │ │ 7. Create RTCPeerConn │ │ │ with ICE servers │ │ │ │ │ │ 8. Generate SDP Offer │ │ │ │ │ │ 9. POST /avatar-offer │ │ │─────────────────────────►│ │ │ │ 10. Encode & Send SDP │ │ │─────────────────────────►│ │ │ │ │ │ 11. session.avatar. │ │ │ connecting │ │ │ (SDP answer) │ │ 12. SDP Answer │◄─────────────────────────│ │◄─────────────────────────│ │ │ │ │ │ 13. setRemoteDescription │ │ │ │ │ │ 14. WebRTC Handshake │ │ │◄─────────────────────────┼─────────────────────────►│ │ (Direct Connection) │ │ │ │ │ │ 15. Video/Audio Stream │ │ │◄────────────────────────────────────────────────────│ │ (Bypasses Backend) │ │ ``` For more technical details, refer to the technical details behind the implementation, refer to the GitHub Repo shared in this post. Here is a video of the demo of the application in action.
Using the Voice Live API in Azure AI Foundry
In this blog post, we’ll explore the Voice Live API from Azure AI Foundry. Officially released for general availability on October 1, 2025, this API unifies speech recognition, generative AI, and text-to-speech capabilities into a single, streamlined interface. It removes the complexity of manually orchestrating multiple components and ensures a consistent developer experience across all models, making it easy to switch and experiment. What sets Voice Live API apart are its advanced conversational enhancements, including: Semantic Voice Activity Detection (VAD) that’s robust against background noise and accurately detects when a user intends to speak. Semantic end-of-turn detection that supports natural pauses in conversation. Server-side audio processing features like noise suppression and echo cancellation, simplifying client-side development. Let’s get started. 1. Getting Started with Voice Live API The Voice Live API ships with an SDKthat lets you open a single realtime WebSocket connection and then do everything—stream microphone audio up, receive synthesized audio/text/function‑call events down— without writing any of the low-level networking plumbing. This is how the connection is opened with the Python SDK. from azure.ai.voicelive.aio import connect from azure.core.credentials import AzureKeyCredential async with connect( endpoint=VOICE_LIVE_ENDPOINT, # https://<your-foundry-resource>.cognitiveservices.azure.com/ credential=AzureKeyCredential(VOICE_LIVE_KEY), model="gpt-4o-realtime", connection_options={ "max_msg_size": 10 * 1024 * 1024, # allow streamed PCM "heartbeat": 20, # keep socket alive "timeout": 20, # network resilience }, ) as connection: Notice that you don't need an underlying deployment nor manage any generative AI models, as the API handles all the underlying infrastructure. Immediately after connecting, declare what kind of conversation you want. This is where you “teach” the session the model instructions, which voice to synthesize, what tool functions it may call, and how to detect speech turns: from azure.ai.voicelive.models import ( RequestSession, Modality, AzureStandardVoice, InputAudioFormat, OutputAudioFormat, AzureSemanticVad, ToolChoiceLiteral, AudioInputTranscriptionOptions ) session_config = RequestSession( modalities=[Modality.TEXT, Modality.AUDIO], instructions="Assist the user with account questions succinctly.", voice=AzureStandardVoice(name="alloy", type="azure-standard"), input_audio_format=InputAudioFormat.PCM16, output_audio_format=OutputAudioFormat.PCM16, turn_detection=AzureSemanticVad( threshold=0.5, prefix_padding_ms=300, silence_duration_ms=500 ), tools=[ # optional { "name": "get_user_information", "description": "Retrieve profile and limits for a user", "input_schema": { "type": "object", "properties": {"user_id": {"type": "string"}}, "required": ["user_id"] } } ], tool_choice=ToolChoiceLiteral.AUTO, input_audio_transcription=AudioInputTranscriptionOptions(model="whisper-1"), ) await connection.session.update(session=session_config) After session setup, it is pure event-driven flow: async for event in connection: if event.type == ServerEventType.RESPONSE_AUDIO_DELTA: playback_queue.put(event.delta) elif event.type == ServerEventType.CONVERSATION_ITEM_CREATED and event.item.type == ItemType.FUNCTION_CALL: handle_function_call(event) That’s the core: one connection, one session config message, then pure event-driven flow. 2. Deep Dive: Tool (Function) Handling in the Voice Live SDK In the Voice Live context, “tools” are model-invocable functions you expose with a JSON schema. The SDK streams a structured function call request (name + incrementally streamed arguments), you execute real code locally, then feed the JSON result back so the model can incorporate it into its next spoken (and/or textual) turn. Let’s unpack the full lifecycle. First, the model emits a CONVERSATION_ITEM_CREATED event whose item.type == FUNCTION_CALL if event.item.type == ItemType.FUNCTION_CALL: await self._handle_function_call_with_improved_pattern(event, connection) Arguments stream (possibly token-by-token) until the SDK signals RESPONSE_FUNCTION_CALL_ARGUMENTS_DONE. Optionally, the SDK may also complete the “response” segment with RESPONSE_DONE before you run the tool. Then we execute the local Python function, and explicitly request a new model response via connection.response.create(), telling the model to incorporate the tool result into a natural-language (and audio) answer. async def _handle_function_call(self, created_evt, connection): call_item = created_evt.item # ResponseFunctionCallItem name = call_item.name call_id = call_item.call_id prev_id = call_item.id # 1. Wait until arguments are fully streamed args_done = await _wait_for_event( connection, {ServerEventType.RESPONSE_FUNCTION_CALL_ARGUMENTS_DONE} ) assert args_done.call_id == call_id arguments = args_done.arguments # JSON string # 2. (Optional) Wait for RESPONSE_DONE to avoid race with model finishing segment await _wait_for_event(connection, {ServerEventType.RESPONSE_DONE}) # 3. Execute func = self.available_functions.get(name) if not func: # Optionally send an error function output return result = await func(arguments) # Implementations are async in this sample # 4. Send output output_item = FunctionCallOutputItem(call_id=call_id, output=json.dumps(result)) await connection.conversation.item.create( previous_item_id=prev_id, item=output_item ) # 5. Trigger follow-up model response await connection.response.create() 3. Sample App: Try the repo with sample app we have created, together with all the infrastructure required already automated. This sample app simulates a friendly real‑time contact‑center rep who can listen continuously, understand you as you speak, instantly look up things like your credit card’s upcoming due date or a product detail via function calls, and then answer back naturally in a Brazilian Portuguese neural voice with almost no lag. Behind the scenes it streams your microphone audio to Azure’s Voice Live (GPT‑4o realtime) model, transcribes and reasons on the fly, selectively triggers lightweight “get user information” or “get product information” lookups to Azure AI Search , and speaks responses right back to you. Happy Coding!The Future of AI: How Lovable.dev and Azure OpenAI Accelerate Apps that Change Lives
Discover how Charles Elwood, a Microsoft AI MVP and TEDx Speaker, leverages Lovable.dev and Azure OpenAI to create impactful AI solutions. From automating expense reports to restoring voices, translating gestures to speech, and visualizing public health data, Charles's innovations are transforming lives and democratizing technology. Follow his journey to learn more about AI for good.Announcing Live Interpreter API - Now in Public Preview
Today, we’re excited to introduce Live Interpreter –a breakthrough new capability in Azure Speech Translation – that makes real-time, multilingual communication effortless. Live Interpreter continuously identifies the language being spoken without requiring you to set an input language and delivers low latency speech-to-speech translation in a natural voice that preserves the speaker’s style and tone.
Latest Avatar Updates: 4K Support and Emotion Control Features
📺 4K Support: Higher Resolution, More Possibilities Our standard avatar offering is 1080P, which performs effectively across both web and mobile applications. However, to accommodate customers who require higher resolution avatars suited for larger displays, we have introduced the custom avatar 4K avatar option. As a quick recap, a custom avatar allows you to create a personalized digital persona using your own assets and configurations, giving you full control over appearance and behavior. The custom avatars are built through self-service workflow, making it easy to generate and deploy avatars tailored to your needs. For a detailed walkthrough of creating a custom avatar, check out our previous blog: Create a Custom Text-to-Speech Avatar Through Self-Service A 4K avatar is created using video training data with 4K resolution, resulting in higher detail accuracy compared to lower resolutions. The fidelity differences between a 4K avatar and a 1080p avatar can be observed in these samples. 4k detail zoom in video sample 1080p detail zoom in video sample And here are videos showcasing how customers such as W2M and ServiceNow are using 4k custom avatar solution on the big screen. And ServiceNow video. The 4K avatar works in both landscape and portrait modes. Landscape 4K suits bigger screens and presentations, while Portrait 4K is ideal for mobile devices, vertical signs, and social media. Training a 4K custom avatar You can train a 4K avatar using the self-serve tool in Azure AI Foundry. Go on to the Azure AI Foundry and log in with your azure account, create AI Foundry resource in one of these 3 service regions: West US 2, West Europe, or Southeast Asia. In Fine-tuning, go to the AI Service fine-tuning tab, you can create a custom avatar by clicking the Fine-tune button and selecting Custom Avatar in the pop-up list. Create a new avatar task, set up the avatar talent, and during the upload data step ensure the videos are at least 2160p to train a 4K avatar. During the model training phase, you may select either landscape or portrait orientation and choose between 1080p or 4K resolution when submitting a new model for training. Tips for 4K avatar training: The 4K avatar model requires 4K video footage, while the portrait dimension model needs portrait-oriented video footage for training. When recording 4K videos, it is important to ensure that body movements remain centered within the frame. How to Synthesize 4K Video By default, the 4K model produces video at a resolution of 3840x2160. However, you may adjust the output resolution while maintaining the original aspect ratio to suit your requirements. For instance, setting the output resolution to 1920x1080 during streaming can help reduce network bandwidth consumption. Code example: const videoFormat = new SpeechSDK.AvatarVideoFormat(); videoFormat.width = 1920; videoFormat.height = 1080; For further details, please refer to the following link: https://github.com/Azure-Samples/cognitive-services-speech-sdk/blob/0d852b2115e780cfb4b65343e6c23e67953e8f4e/samples/js/browser/avatar/js/basic.js#L224C1-L225C1 Pricing See our pricing page Azure AI Speech Pricing | Microsoft Azure for details on 4K avatar charges. 🎭 Avatar Emotion control: Voice & Visuals in Sync A new feature for avatar emotion control has been implemented. This functionality enables users to set the avatar’s emotion, which will be reflected in both the voice and facial expression. This new feature can be experienced in the lisa-casual-standing avatar in batch mode, and may be accessed through the following methods: Access through AI Foundry portal In Azure AI Foundry, in the Text to Speech avatar tool, users can select the Lisa-casual-standing avatar. Since this avatar supports emotion controls, an Emotion drop-down menu appears above the text box, listing all available emotions for the voice. Changing the voice will update the emotion options according to the supported emotions for each voice. Access through SSML Example to specify emotion during synthesis in SSML: <speak xmlns=\"http://www.w3.org/2001/10/synthesis\" xmlns:mstts=\"http://www.w3.org/2001/mstts\" xmlns:emo=\"http://www.w3.org/2009/10/emotionml\" version=\"1.0\" xml:lang=\"en-US\"> <voice name=\"en-US-SaraNeural\"> <mstts:express-as style=\"angry\">I'm angry because I care, and it hurts to see things fall apart like this.</mstts:express-as> </voice> </speak> Facial expressions are determined by the selected voice emotion. Consequently, users are required to specify the desired voice emotion prior to use. If the chosen voice does not support any available voice emotions, or if no emotion is selected, the system will default to a "neutral" emotion, and the avatar will speak with a neutral expression. The following voice emotions are currently supported for synchronizing with avatar expressions. Cheerful Shouting Friendly Unfriendly Hopeful Disgruntled Funny Surprised Angry Excited Samples Watch the demo video featuring Lisa Casual Standing with emotion control enabled. The video demonstrates how adjustments in tone and facial expression affect the avatar's appearance. Several samples are included to show the outcome of different emotion settings. Custom avatar emotion support Next, we will enable custom avatars with emotion control and preview the feature with a few customers first. Please contact us if you want to build emotion control avatar models. Subjective evaluation An Expressiveness Mean Opinion Score test was used to evaluate perceptual quality, measuring how effectively the speaker conveys emotions, intentions, and natural expressions through facial movements and tone. This score indicates how engaging and lifelike the speaker appears in the video. Solution Expressiveness MOS↑ Lisa-casual-standing 4.15 Company A 3.88 This update represents substantial progress toward enhancing avatars to be more realistic, expressive, and adaptable for varied content requirements. We look forward to observing the innovative applications users will develop with these advancements.
Project Maria: Bringing Speech and Avatars Together for Next-Generation Customer Experiences
In an age where digital transformation influences nearly every aspect of business, companies are actively seeking innovative ways to differentiate their customer interactions. Traditional text-based chatbots, while helpful, often leave users wanting a more natural, personalized, and efficient experience. Imagine hosting a virtual brand ambassador—a digital twin of yourself or your organization’s spokesperson—capable of answering customer queries in real time with a lifelike voice and expressive 2D or 3D face. This is where Project Maria comes in. Project Maria is an internal Microsoft initiative that integrates cutting-edge speech-to-text (STT), text-to-speech (TTS), large language model and avatar technologies. Using Azure AI speech and custom neural voice models, it seeks to create immersive, personalized interactions for customers—reducing friction, increasing brand loyalty, and opening new business opportunities in areas such as customer support, product briefings, digital twins, live marketing events, safety briefings, and beyond. In this blog post, we will dive into: The Problem and Rationale for evolving beyond basic text-based solutions. Speech-to-Text (STT), Text-to-Speech (TTS) Pipelines, Azure OpenAI GPT-4o Real-Time API that power natural conversations. Avatar Models in Azure, including off-the-shelf 2D avatars and fully customized custom avatar Neural Voice Model Creation, from data gathering to training and deployment on Azure. Security and Compliance considerations for handling sensitive voice assets and data. Use Cases from customer support to digital brand ambassadors and safety briefings. Real-World Debut of Project Maria, showcased at the AI Leaders’ Summit in Seattle. Future Outlook on how custom avatar will reshape business interactions, scale presence, and streamline time-consuming tasks. If you’re developing or considering a neural (custom) voice + avatar models for your product or enterprise, this post will guide you through both conceptual and technical details to help you get started—and highlight where the field is heading next. 1. The Problem: Limitations of Text-Based Chatbots 1.1 Boredom and Fatigue in Text Interactions Text-based chatbots have come a long way, especially with the advent of powerful Large Language Models (LLMs) and Small Large Models (SLMs). Despite these innovations, interactions can still become tedious—often requiring users to spend significant personal time crafting the right questions. Many of us have experienced chatbots that respond with excessively verbose or repetitive messages, leading to boredom or even frustration. In industries that demand immediacy—like healthcare, finance, or real-time consumer support—purely text-based exchanges can feel slow and cumbersome. Moreover, text chat requires a user’s full attention to read and type, whether in a busy contact center environment or an internal knowledge base where employees juggle multiple tasks. 1.2 Desire for More Engaging and Efficient Modalities Today’s users expect something closer to human conversation. Devices ranging from smartphones to smart speakers and in-car infotainment systems have normalized voice-based interfaces. Adding an avatar—whether a 2D or 3D representation—deepens engagement by combining speech with a friendly visual persona. This can elevate brand identity: an avatar that looks, talks, and gestures like your company’s brand ambassador or a well-known subject-matter expert. 1.3 The Need for Scalability In a busy customer support environment, human representatives simply can’t handle an infinite volume of conversations or offer 24/7 coverage across multiple channels. Automation is essential, yet providing high-quality automated interactions remains challenging. While a text-based chatbot might handle routine queries, a voice-based, avatar-enabled agent can manage more complex requests with greater dynamism and personality. By giving your digital support assistant both a “face” and a voice aligned with your brand, you can foster deeper emotional connections and provide a more genuine, empathetic experience. This blend of automation and personalization scales your support operations, ensuring higher customer satisfaction while freeing human agents to focus on critical or specialized tasks. 2. The Vision: Project Maria’s Approach Project Maria addresses these challenges by creating a unified pipeline that supports: Speech-to-Text (STT) for recognizing user queries quickly and accurately. Natural Language Understanding (NLU) layers (potentially leveraging Azure OpenAI or other large language models) for comprehensive query interpretation. Text-to-Speech (TTS) that returns highly natural-sounding responses, possibly in multiple languages, with customized prosody and style. Avatar Rendering, which can be a 2D animated avatar or a more advanced 3D digital twin, bringing personality and facial expressions to the conversation. By using Azure AI Services—particularly the Speech and Custom Neural Voice offerings—can deliver brand-specific voices. This ensures that each brand or individual user’s avatar can match (or approximate) a signature voice, turning a run-of-the-mill voice assistant into a truly personal digital replicas 3. Technical Foundations 3.1 Speech-to-Text (STT) At the heart of the system is Azure AI Services for Speech, which provides: Real-time transcription capabilities with a variety of languages and dialects. Noise suppression, ensuring robust performance in busy environments. Streaming APIs, critical for real-time or near-real-time interactions. When a user speaks, audio data is captured (for example, via a web microphone feed or a phone line) and streamed to the Azure service. The recognized text is returned in segments, which the NLU or conversation manager can interpret. 3.1.1 Audio Pipeline Capture: The user’s microphone audio is captured by a front-end (e.g., a web app, mobile app, or IoT device). Pre-processing: Noise reduction or volume normalization might be applied locally or in the cloud, ensuring consistent input. Azure STT Ingestion: Data is sent to the Speech service endpoint, authenticated via subscription keys or tokens (more on security later). Result Handling: The recognized text arrives in partial hypotheses (partial transcripts) and final recognized segments. Project Maria (Custom Avatar) processes these results to understand user intent 3.2 Text-to-Speech (TTS) Once an intent is identified and a response is formulated, the system needs to deliver speech output. Standard Neural Voices: Microsoft provides a wide range of prebuilt voices in multiple languages. Custom Neural Voice: For an even more personalized experience, you can train a voice model that matches a brand spokesperson or a distinct voice identity. This is done using your custom datasets, ensuring the final system speaks exactly like the recorded persona. 3.2.1 Voice Font Selection and Configuration In a typical architecture: The conversation manager (which could be an orchestrator or a custom microservice) provides the text output to the TTS service. The TTS service uses a configured voice font—like en-US-JennyNeural or a custom neural voice ID (like Maria Neural Voice) if you have a specialized voice model. The synthesized audio is returned as an audio stream (e.g., PCM or MP3). You can play this in a webpage directly or in a native app environment. Azure OpenAI GPT-4o Real-Time API integrates with Azure's Speech Services to enable seamless interactions. First, your speech is transcribed in near real time. GPT-4o then processes this text to generate context-aware responses, which are converted to natural-sounding audio via Azure TTS. This audio is synchronized with avatar models to create a lifelike, engaging interface 3.3 Real-Time Conversational Loop Maria is designed for real-time or text to speech conversations. The user’s speech is continuously streamed to Azure STT. The recognized text triggers a real-time inference step for the next best action or response. The response is generated by Azure OpenAI model (like GPT-4o) or other LLM/SLM The text is then synthesized to speech, which the user hears with minimal latency. 3.4 Avatars: 2D and Beyond 3.4.1 Prebuilt Azure 2D Avatars Azure AI Speech Services includes an Avatar capability that can be activated to display a talking head or a 2D animated character. Developers can: Choose from prebuilt characters or import basic custom animations. Synchronize lip movements to the TTS output. Overlay brand-specific backgrounds or adopt transparency for embedding in various UIs. 3.4.2 Fully Custom Avatars (Customer Support Agent Like Maria) For organizations wanting a customer support agent, subject-matter expert, or brand ambassador: Capture: Record high-fidelity audio and video of the person you want to replicate. The more data, the better the outcome (though privacy and licensing must be considered). Modeling: Use advanced 3D or specialized 2D animation software (or partner with Microsoft’s custom avatar creation solutions) to generate a rigged model that matches the real person’s facial geometry and expressions. Integration: Once the model is rigged, it can be integrated with the TTS engine. As text is converted to speech, the avatar automatically animates lip shapes and facial expressions in near real time. 3.5 Latency and Bandwidth Considerations When building an interactive system, keep an eye on: Network latency: Real-time STT and TTS require stable, fast connections. Compute resources: If hosting advanced ML or high concurrency, scaling containers (e.g., via Docker and Kubernetes) is critical. Avatars: Real-time animation might require sending frames or instructions to a client’s browser or device. 4. Building the Model: Neural Voice Model Creation 4.1 Data Gathering To train a custom neural voice, you typically need: High-quality audio clips: Ideally recorded in a professional studio to minimize background noise, with the same microphone setup throughout. Matching transcripts for each clip. Minimum data duration: Microsoft recommends a certain threshold (e.g., 300+ utterances, typically around 30 minutes to a few hours of recorded speech, depending on the complexity of the final voice needed). 4.2 Training Process Data Upload: Use the Azure Speech portal or APIs to upload your curated dataset. Model Training: Azure runs training jobs that often require a few hours (or more). This step includes: Acoustic feature extraction (spectrogram analysis). Language or phoneme modeling for the relevant language and accent. Prosody tuning, ensuring the voice can handle various styles (cheerful, empathetic, urgent, etc.). Quality Checks: After training, you receive an initial voice model. You can generate test phrases to assess clarity, intonation, and overall quality. Iteration: If the voice quality is not satisfactory, you gather more data or refine the existing data (removing noisy segments or inaccurate transcripts). 4.3 Deployment Once satisfied with the custom neural voice: Deploy the model to an Azure endpoint within your subscription. Configure your TTS engine to use the custom endpoint ID instead of a standard voice. 5. Securing Avatar and Voice Models Security is paramount when personal data, brand identity, or intellectual property is on the line. 5.1 API Keys and Endpoints Azure AI Services requires an API key or an OAuth token to access STT/TTS features. Store keys in Azure Key Vault or as secure environment variables. Avoid hard-coding them in the front-end or source control. 5.2 Access Control Role-Based Access Control (RBAC) at both Azure subscription level and container (e.g., Docker or Kubernetes) level ensures only authorized personnel can deploy or manage the containers running these services. Network Security: Use private endpoints if you want to limit exposure to the public internet. 5.3 Intellectual Property Concerns Avatar and Voice Imitation: A avatar model and custom neural voice that mimics a specific individual must be authorized by that individual. Azure has a verification process in place to ensure consent. Data Storage: The training audio data and transcripts must be securely stored, often with encryption at rest and in transit. 6. Use Cases: Bringing It All Together 6.1 Customer Support A digital avatar that greets users on a website or mobile app can handle first-level queries: “Where can I find my billing information?” “What is your return policy?” By speaking these answers aloud with a friendly face and voice, the experience is more memorable and can reduce queue times for human agents. If the question is too complex, the avatar can seamlessly hand off to a live agent. Meanwhile, transcripts of the entire conversation are stored (e.g., in Azure Cosmos DB), enabling data analytics and further improvements to the system. 6.2 Safety Briefings and Public Announcements Industries like manufacturing, aviation, or construction must repeatedly deliver consistent safety messages. A personal avatar can recite crucial safety protocols in multiple languages, ensuring nothing is lost in translation. Because the TTS voice is consistent, workers become accustomed to the avatar’s instructions. Over time, you could even create a brand or site-specific “Safety Officer” avatar that fosters familiarity. 6.3 Digital Twins at Live Events Suppose you want your company’s spokesperson to simultaneously appear at multiple events across the globe. With a digital twin: The spokesperson’s avatar and voice “present” in real time, responding to local audience questions. This can be done in multiple languages, bridging communication barriers instantaneously. Attendees get a sense of personal interaction, while the real spokesperson can focus on core tasks, or appear physically at another event entirely. 6.4 AI Training and Education In e-learning platforms, a digital tutor can guide students through lessons, answer questions in real time, and adapt the tone of voice based on the difficulty of the topic or the student’s performance. By offering a face and voice, the tutor becomes more engaging than a text-only system. 7. Debut: Maria at the AI Leaders Summit in Seattle Project Maria had its first major showcase at the AI Leaders Summit in Seattle last week. We set up a live demonstration: Live Conversations: Attendees approached a large screen that displayed Maria’s 2D avatar. On-the-Fly: Maria recognized queries with STT, generated text responses from an internal knowledge base (powered by GPT-4o or domain-specific models), then spoke them back with a custom Azure neural voice. Interactive: The avatar lip-synced to the output speech, included animated gestures for emphasis, and even displayed text-based subtitles for clarity. The response was overwhelmingly positive. Customers praised the fluid voice quality and the lifelike nature of Maria’s avatar. Many commented that they felt they were interacting with a real brand ambassador, especially because the chosen custom neural voice had just the right inflections and emotional range. 8. Technical Implementation Details Below is a high-level architecture of how Project Maria might be deployed using containers and Azure resources. Front-End Web App: Built with a modern JavaScript framework (React, Vue, Angular, etc.). Captures user audio through the browser’s WebRTC or MediaStream APIs. Connects via WebSockets or RESTful endpoints for STT requests. Renders the avatar in a <canvas> element or using a specialized avatar library. Backend: Containerized with Docker. Exposes endpoints for STT streaming (optionally passing data directly to Azure for transcription). Integrates with the TTS service, retrieving synthesized audio buffers. Returns the audio back to the front-end in a continuous stream for immediate playback. Avatar Integration: The back-end or a specialized service handles lip-sync generation (e.g., via phoneme mapping from the TTS output). The front-end renders the 2D or 3D avatar in sync with the audio playback. This can be done by streaming timing markers that indicate which phoneme is currently active. Data and Conversation Storage: Use an Azure Cosmos DB or a similar NoSQL solution to store transcripts, user IDs, timestamps, and optional metadata (e.g., conversation sentiment). This data can later be used to improve the conversation model, evaluate performance, or train advanced analytics solutions. Security: All sensitive environment variables (like Azure API keys) are loaded securely, either through Azure Key Vault or container orchestration secrets. The system enforces user authentication if needed. For instance, an internal HR system might restrict the avatar-based service to employees only. Scaling: Deploy containers in Azure Kubernetes Service (AKS), setting up auto-scaling to handle peak loads. Monitor CPU/memory usage, as well as TTS quota usage. For STT, ensure the service tier can handle simultaneous requests from multiple users. 9. Securing Avatar Models and Voice Data 9.1 Identity Management Each avatar or custom neural voice is tied to a specific subscription. Using Azure Active Directory (Azure AD), you can give fine-grained permissions so that only authorized DevOps or AI specialists can alter or redeploy the voice. 9.2 API Gateways and Firewalls For enterprise contexts, you might place an API Gateway in front of your containerized services. This central gateway can: Inspect requests for anomalies, Enforce rate-limits, Log traffic to meet compliance or auditing requirements. 9.3 Key Rotation and Secrets Management Frequently rotates keys to minimize the risk of compromised credentials. Tools like Azure Key Vault or GitHub’s secret storage features can automate the rotation process, ensuring minimal downtime. 10. The Path Forward: Scaling Custom Avatar 10.1 Extended Personalization While Project Maria currently focuses on voice and basic facial expressions, future expansions include: Emotion Synthesis: Beyond standard TTS expressions (friendly, sad, excited), we can integrate emotional AI to dynamically adjust the avatar’s tone based on user sentiment. Gesture Libraries: 2D or 3D avatars can incorporate hand gestures, posture changes, or background movements to mimic a real person in conversation. This reduces the “uncanny valley” effect. 10.2 Multilingual, Multimodal As businesses operate globally, multilingual interactions become paramount. We have seen many use cases to: Auto-detect language from a user’s speech and respond in kind. Offer real-time translation, bridging non-English speakers to brand content. 10.3 Agent Autonomy Systems like Maria won’t just respond to direct questions; they can initiate proactivity: Send voice-based notifications or warnings when critical events happen. Manage long-running tasks such as scheduling or triaging user requests, akin to an “executive assistant” for multiple users simultaneously. 10.4 Ethical and Social Considerations With near-perfect replicas of voices, there is a growing concern about identity theft, misinformation, and deepfakes. Companies implementing digital twins must: Secure explicit consent from individuals. Implement watermarking or authentication for voice data. Educate customers and employees on usage boundaries and disclaimers 11. Conclusion Project Maria represents a significant leap in how businesses and organizations can scale their presence, offering a humanized, voice-enabled digital experience. By merging speech-to-text, text-to-speech, and avatar technologies, you can: Boost Engagement: A friendly face and familiar voice can reduce user fatigue and build emotional resonance. Extend Brand Reach: Appear in many locations at once via digital twins, creating personalized interactions at scale. Streamline Operations: Automate repetitive queries while maintaining a human touch, freeing up valuable employee time. Ensure Security and Compliance: By using Azure’s robust ecosystem of services and best practices for voice data. As demonstrated at the AI Leaders Summit in Seattle, Maria is already reshaping how businesses think about communication. The synergy of avatars, neural voices, and secure, cloud-based AI is paving the way for the next frontier in customer interaction. Looking ahead, we anticipate that digital twins—like Maria—will become ubiquitous, automating not just chat responses but a wide range of tasks that once demanded human presence. From personalized marketing to advanced training scenarios, the possibilities are vast. In short, the fusion of STT, TTS, and avatar technologies is more than a novel gimmick; it is an evolution in human-computer interaction. By investing in robust pipelines, custom neural voice training, and carefully orchestrated containerized deployments, businesses can unlock extraordinary potential. Project Maria is our blueprint for how to do it right—secure, customizable, and scalable—helping organizations around the world transform user experiences in ways that are both convenient and captivating. If you’re looking to scale your brand, innovate in human-machine dialogues, or harness the power of digital twins, we encourage you to explore Azure AI Services’ STT, TTS, and Avatar solutions. Together, these advancements promise a future where your digital self (or brand persona) can meaningfully interact with users anytime, anywhere. Detailed Technical Implementation:- https://learn.microsoft.com/en-us/azure/ai-services/speech-service/text-to-speech-avatar/what-is-custom-text-to-speech-avatar Text to Speech with Multi-Agent Orchestration Framework:- https://github.com/ganachan/Project_Maria_Accelerator_tts Contoso_Maria_Greetings.mp4
Introducing AI-generated voices for Azure neural text to speech service
In this blog, we introduce two new voices created using the latest controllable new voice generation technology, a masculine voice named AIGenerate1 and a feminine voice named AIGenerate2, and provide a deeper view on the technology behind.
New technical research is advancing Azure’s Neural Text-to-Speech service
Our latest research innovation, code named NaturalSpeech, brings a new milestone to neural TTS achieving no significant difference with natural human recordings using side-by-side CMOS as metrics on a popular TTS dataset (LJSpeech) for the first time.
