How Loka Built a Natural, Low-Latency Voice Agent with Amazon Nova 2 Sonic

This article describes how Loka built a natural, low-latency voice agent using Amazon Nova 2 Sonic that transforms customer interactions for automotive dealerships.

• Native speech-to-speech models process audio end-to-end, capturing tone and emotion that text-only pipelines miss
• Nova 2 Sonic achieved 87.0 speech reasoning score on Big Bench Audio, outperforming Gemini 2.5 Flash (71.0) and GPT Realtime (83.0)
• Time to first audio of 1.39 seconds enables natural "barge-in" behavior and human-like conversation patterns
• Costs approximately $0.27 per hour of input audio, lower than comparable real-time models
• Prompt engineering iterations improved overall judge score from 2.7 to 3.8 through better turn discipline and behavioral boundaries
• Serverless architecture uses LiveKit, AWS Fargate, Amazon RDS, ElastiCache, and Bedrock for production deployment
• Real-world testing across customer personas averaged 4.0 overall score, with edge cases like angry and confused customers scoring 4.5

Speech-to-speech AI has reached production readiness, enabling industries requiring real-time intelligent voice interactions to deliver immediate, helpful responses and handle complex requests smoothly.