Empirical evidence of Large Language Model's influence on human spoken communication
This study investigates whether large language models (LLMs), such as ChatGPT, reshape human spoken language and cultural practices through human–AI linguistic feedback loops. Method: Leveraging ASR-transcribed speech from 280,000 university-level YouTube lecture videos, we conduct time-series word frequency analysis and employ a pre–post ChatGPT release quasi-experimental design. Contribution/Results: We present the first empirical evidence that LLMs directly influence authentic human spoken behavior: post-release, ChatGPT-characteristic lexical items exhibit statistically significant increases in academic speech (p < 0.001), confirming systematic oral imitation by humans. Moving beyond prior written-language–focused work, this study reveals the mechanism of AI-generated language diffusion into spoken discourse. It further highlights critical sociocultural risks—including erosion of linguistic diversity, discursive manipulation, and asymmetric human–AI co-evolution—thereby advancing foundational understanding of LLMs’ real-world linguistic impact.