Voice agent architecture: cascaded ASR-LLM-TTS control vs end-to-end latency

Informal-Dust4499 · reddit · 2026-09-15

A builder lays out the fundamental voice-agent tradeoff: latency vs control. Cascaded pipelines (ASR → LLM → TTS) expose text between components for context injection, policy enforcement, logging, and tool calls — but stack latency, and a 2-second pause that's fine in chat feels long on a call. End-to-end speech-to-speech models fix latency but remove intervention points, which is problematic for customer service flows (identify customer, check refund policy, call APIs, log, escalate). Fine-tuning adds cost; masking latency with filler phrases doesn't solve the problem. Their guess: end-to-end wins once models can ingest mid-conversation context and emit structured tool calls alongside voice.

Original post →

More from coding & agent

coding & agent channel →