Non-Verbal Auditory Input for Controlling Binary, Discrete, and Continuous Input in Automotive User Interfaces.

Using auditory input while driving is becoming increasingly popular for making distraction-free inputs while driving. However, we argue that auditory input is more than just using speech. Thus, in this work, we explore using Non-Verbal Auditory Input (NVAI) for interacting with smart assistants while driving. Through an online study with 100 participants, we initially investigated users' input preferences for binary, discrete, and continuous data types. After identifying the top three modalities for NVAI, we subsequently conducted an in-person study with 16 participants. In our study, the participants tested these input modalities for three different input data types regarding their accuracy, driver-distraction, and social acceptability, while operating a driving simulator. The results reveal that, although clapping hands for making input was initially preferred in our online survey, it is snapping fingers for binary input and discrete input and humming for making continuous input that is the preferred NVAI modality while driving.