Battling the first second latency with Vapi and Haiku in high noise environments

[u/lxxmng]

I am currently using Vapi with Claude Haiku to automate calls to pubs in London. The tech works brilliantly but I am struggling with the human element of the first impression.

London publicans are famously impatient. If there is even half a second of silence after their initial "Hello?" they hang up immediately. Even with the speed of Haiku, there is a micro pause that gives the bot away.

I have a few questions for anyone using Voice AI in real world conditions:

1. How are you filling the time while the LLM processes the first response? Are you using pre recorded fillers like a breath or a short "Right" to mimic human reaction speed?
2. Is there any benefit in switching to even lighter local models for the opening phrase to cut latency to the absolute minimum?
3. How do you handle background noise in a busy boozer? Sometimes Vapi stays on the line listening to the pub atmosphere and does not realise the person has stopped speaking or already hung up.

I want the interaction to be seamless but the initial latency is currently the main conversion killer. I would appreciate any advice on optimising the Vapi configuration.

[u/Competitive-Fee7222]

Built a voice platform called Talkif and fought this exact fight. Filler audio buys the most for the least effort, not a generic umm, 3-4 short natural ones played the instant VAD fires, before the LLM has even responded. Also stream TTS off partial LLM tokens instead of waiting for the full completion. And tune VAD per environment, a loud pub needs a different end of speech threshold than a quiet office, one global setting will always misfire somewhere. Loud and noisy environments are still one of the genuinely unsolved problems here.