What changed

AWS announced a new method for streaming low-latency speech from AI agents using the Kokoro TTS model on Amazon SageMaker AI. The solution addresses the issue where text-to-speech integrations wait for full responses before starting synthesis, leading to delays and user frustration. Instead, the system streams each sentence to a hosted Kokoro-82M TTS model as soon as the agent produces it, allowing audio playback to start immediately.

What this means in practice

The solution enables real-time speech synthesis by streaming each sentence to the Kokoro-82M model, which runs on a SageMaker AI real-time endpoint. This model, with 82 million parameters, is designed to run efficiently on a mid-tier GPU instance, keeping both latency and inference costs low. The system supports two transport methods: a unidirectional POST /invocations route for complete input responses and a bidirectional WebSocket /invocations-bidirectional-stream route for handling multiple messages in both directions.

Limitations and availability

The solution requires an AWS account with specific permissions and prerequisites such as an IAM role, an ECR repository, and the AWS CDK v2. The deployment involves setting up a SageMaker AI real-time endpoint with a custom container that includes the Kokoro-82M model. The container uses an older version of PyTorch, which should be upgraded before non-proof-of-value use. The solution is available through the AWS SDK for Python (Boto3) and requires familiarity with WebSockets and ASGI frameworks. The deployment code is provided in a GitHub repository referenced in the post.

Source facts for AWS Introduces Low-Latency Speech Streaming with Kokoro TTS on SageMaker AI: Stream low-latency speech from AI agents using Kokoro TTS on Amazon SageMaker AI A customer asks an AI voice agent a question and waits. The agent already has an answer, it’s midway through generating a long, multi-paragraph response, but the customer hears nothing for five seconds. By the time an answer arrives, the customer is frustrated, confused, and no longer paying attention.
Original AINewsTrend explainer based on the cited source. This graphic summarizes source statements; it is not an independent benchmark.

Sources and further reading

  1. awsml: Stream low-latency speech from AI agents using Kokoro TTS on Amazon SageMaker AI