Domain-Specific Fine-Tuning of PersonaPlex-7b for Customer Persona Simulation
Our research into creating a human-like customer service experience
We fine-tuned NVIDIA's PersonaPlex-7b-v1 model on 200 synthetic coffee shop customer conversations to address hallucinations and poor task adherence in customer-facing deployments. Using LoRA training with ChatterboxTTS audio and LibriSpeech voices, we introduced a semantic-weighted loss function and voice prompt injection mechanism to improve emotional accuracy and reduce role-inversion hallucinations. LLM-as-judge evaluation shows improvements over the base model across all three tested configurations.
February 2026Read paper →