We conduct a randomised control treatment (study) to explore the effects of the introduction of a voice assistant, in collaboration with a large hotel in Shanghai. The voice assistant responds to verbal queries from and provides information to the guests, and also controls the operation of various equipment in the room (including the TV, thermostat and the blinds). While this technology was intended to enhance customer experience, we find evidence for negative effects on customer experience and for the firm. In particular, we find a significant increase in the number and duration of calls to the front desk. This increase is more pronounced for older guests, and for more premium rooms. An analysis of the sentiment in the calls (both manual-based on audio file sample and AI-based on text analysis of all calls) suggest a decline in sentiment (more negative sentiment) after the installation of voice assistants. Our findings are consistent with the presence of adjustment costs, including learning costs for customers, following the introduction of smart technology.