Impact of Voice Variation in Speech-based In-Vehicle Systems on Attitude and Driving Behaviour

Automobile manufacturers are making information systems available in all vehicles. Most systems are screen based, but increasingly systems are either hybrids (screen/speech) or speech based. Speech systems in vehicles may have advantages over screen based in-vehicle systems; literature suggests that speech can be less distracting than screen-based interactions. Nonetheless, using speech systems in the car also introduces social and attitudinal effects. Voices are not neutral! Voices carry socio-economic cues including indicators of gender, age, personality, emotional state, ethniticity, education and social status. Perception of information presented by the voice is influenced by the perception of the voice demographics. This is further complicated by different individuals perceiving voices in different ways. A voice that is seen as positive by one individual can be perceived negatively by another. We present results from a number of driving simulator studies of speech based in-vehicle systems. These studies show that speech based in-vehicle systems can affect drivers’ attitude and driving performance. Attitude and performance can be improved, but the effect of the voice can also prove harmful for driving behaviour and driving safety. This makes it important to include the voice as a design parameter of speech-based in-vehicle systems. Voices and Speech-based In-Vehicle Systems Automobile manufacturers, electronics and telecommunications companies are making computer based information systems available in all vehicles. Most cars today are fitted with interactive information systems including high quality audio/video systems, satellite navigation systems, handsfree telephony, and control over climate and car behaviour (Floudas, et al., 2004). Even though most in-vehicle systems are screen-based, speech interactions are becoming more commonly used by in-vehicle systems. The use of speech technology in a vehicle would help increase the number of features and systems that can be controlled. There is limited space on steering wheel and dashboard for buttons. It would also enable drivers to keep their hands on the steering wheel and their eyes on the road during interactions with the system.