Apple has responded to a University of Utah study which criticized the safety of using Siri while driving, stating that it didn’t test the company’s in-car versions, Siri Eyes Free and CarPlay.

Of the six speech-recognition systems tested by researchers, Siri was found to be the worst for driver distraction. The study hooked up drivers to heart-rate monitors and other equipment designed to measure the degree of stress experienced by drivers while carrying out a range of voice-command tasks, giving each system a distraction rating from 1 (best) to 5 (worst) …

The WSJ reported last month that Siri had the worst score, with a distraction rating of 4.

Even the best of the tested systems, Toyota’s Entune, scored a 1.7 “cognitive distraction ranking,” the study found, compared to a 1 level for listening to the radio. The worst of the tested in-dash systems, Chevy’s MyLink, scored a 3.7. Worst of all, the researchers concluded, was Apple’s Siri, which came in at a frustration/distraction level of 4.

Apple has now responded, stating that while the study examined dedicated in-car systems from most manufacturers, it did not test the car-specific versions of Siri.

CarPlay and Siri Eyes Free intuitively use your vehicle’s native controls so you don’t need to pick-up and look at your phone while driving. These experiences are tailored so you only have access to iPhone apps that are optimized for the car and make sense for an in-vehicle experience.

A range of studies cited in the latest WSJ piece do, however, conclude that while using voice commands for things like controlling infotainment systems is safer than operating controls manually, that only reduces, rather than eliminates, the risk of distraction.

Our own review of CarPlay based on the first after-market solution concluded that it has promise, but has some way yet to go. Apple and its car manufacturer partners appear to agree, earlier promises of 2014 availability having been quietly removed from its CarPlay microsite.

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