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Boost car safety with front-end voice activation

Posted: 31 Oct 2011 ?? ?Print Version ?Bookmark and Share

Keywords:voice activation? user interface? Text-To-Speech?

Vehicles are inherently dangerous. These are two-ton masses of metal shooting along at 30-plus miles an hour and controlled by distracted people trying to do far too many things at once. The real problem for drivers is the distractions, and the desire for additional productivity or entertainment that creates them. Much debate has gone on about what causes driver distraction. Mental distractions take our minds off of driving, visual distractions take our eyes off the road, and physical distractions take our hands off the wheel.

Mental distraction has caused the greatest controversy. For example, does voice dialing really help if we're just going to end up talking on a speakerphone and be distracted mentally? If we really want our cars to be safe, then we shouldn't think and drive but we'll never get legislation that outlaws singing along with the radio or requires us to limit our thoughts while driving. The mental distractions, although quite serious, are somewhat unavoidable. Fortunately, visual distractions and physical distractions can be reduced through voice user interfaces that allow us to control our car without looking over at knobs and buttons, and without having to reach out and touch them.

Unfortunately, most implementations of speech recognition in cars have required buttons to activate the recognition. Many design approaches to the automotive speech recognition user experience have centered on "where to put the button?" The automotive industry has been resigned to have a button press and the winning solution has been to place it on the wheel so it is convenient. A new generation of speech technologies including truly hands-free voice controls are now emerging that enable complete avoidance of buttons, allowing drivers to better keep their eyes on the road and hands on the wheel.

Creating voice UI
To create a truly hands-free, eyes-free user experience, there are a number of technology stages that need to be addressed.

voice recognition

Figure: Key components of the most natural user interface: speech.

Stage 1: Voice ActivationThis essentially is replacing the button press to permit the driver to keep hands on the wheel and eyes on the road. The "recognizer" needs to be always on and ready to call Stage 2 into operation. But the recognizer must be able to activate in very high noise situations (because the radio may be on loud) and the user shouldn't be forced to lean over to touch volume controls to make it work.

Another key criterion for this first stage is a very fast responseit must be real time, because if the function is to adequately replace a button, then the response time must be the same as a button, which is near instantaneous. Simple command and control functions can be handled embedded in the car by the Stage 1 recognition system or a more complex Stage 2 system which could be embedded or cloud based.

Stage 2: Speech Recognition and TranscriptionThe more power hungry and powerful Stage 2 recognizer translates what is spoken into text. If the purpose is text messaging or voice dialing, then the process can stop here. If the user wants a question answered or data access then the system moves on to Stage 3.

Recognizers are pretty good at translating, as long as the user speaks in a clear relatively unaccented voice with a good sound to noise ratio (loud voice spoken close to the mic and/or minimal background noise). Recognizers also tend to be best at "grammars" where the query types and phrase structures are well understood and highly predictable. Because the Stage 1 recognizer can respond in high noise, it can drop volume on the in car radio to assist in Stage 2 recognition.

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