  The use of natural language and voice-based interfaces gradu-ally transforms
how consumers search, shop, and express their preferences. The current work
explores how changes in the syntactical structure of the interaction with
conversational interfaces (command vs. request based expression modalities)
negatively affects consumers' subjective task enjoyment and systematically
alters objective vocal features in the human voice. We show that requests (vs.
commands) lead to an in-crease in phonetic convergence and lower phonetic
latency, and ultimately a more natural task experience for consumers. To the
best of our knowledge, this is the first work docu-menting that altering the
input modality of how consumers interact with smart objects systematically
affects consumers' IoT experience. We provide evidence that altering the
required input to initiate a conversation with smart objects provokes
systematic changes both in terms of consumers' subjective experience and
objective phonetic changes in the human voice. The current research also makes
a methodological con-tribution by highlighting the unexplored potential of
feature extraction in human voice as a novel data format linking consumers'
vocal features during speech formation and their sub-jective task experiences.
