The Power of AI-Generated Voices: How Digital Vocal Tract Length Shapes Product Congruency and Ad Performance

Can AI-generated voices be designed to improve product and brand perceptions? Akin to human voices that evoke mental images in a listener even without visual cues, artificially generated voices can be intentionally designed to elicit envisioned mental representations. Drawing from prior work on sound symbolism and computational advances in speech synthesis, the authors explore how the voice of an AI-powered conversational agent (e.g., a voice assistant such as Amazon Alexa) impacts consumer perceptions and choice. Specifically, the authors examine how altering a conversational agent's digital vocal tract length (i.e., timbre) shapes consumers’ physical ascriptions of the agent and subsequent voice–product congruency evaluations. Four experiments, including a large-scale field experiment, demonstrate that increasing (decreasing) the vocal tract length promotes congruency attributions toward stereotypically masculine (feminine) products and improves advertising performance (higher click-through rates and lower costs per click). This article represents a critical first step in deepening understanding on how artificially generated voices shape the consumer experience, demonstrating how firms could enhance product congruency perceptions and advertising performance by leveraging a more theory-driven approach to voice marketing.