“Speech Melody and Speech Content Didn’t Fit Together”—Differences in Speech Behavior for Device Directed and Human Directed Interactions

Nowadays, a diverse set of addressee detection methods is discussed. Typically, wake words are used. But these force an unnatural interaction and are error-prone, especially in case of false positive classification (user says the wake up word without intending to interact with the device). Therefore, technical systems should be enabled to perform a detection of device directed speech. In order to enrich research in the field of speech analysis in HCI we conducted studies with a commercial voice assistant, Amazon’s ALEXA (Voice Assistant Conversation Corpus, VACC), and complemented objective speech analysis with subjective self and external reports on possible differences in speaking with the voice assistant compared to speaking with another person. The analysis revealed a set of specific features for device directed speech. It can be concluded that speech-based addressing of a technical system is a mainly conscious process including individual modifications of the speaking style.