Motorists have been told that using a voice-to-text application is just as dangerous as the conventional method of texting.
In a groundbreaking study conducted by the Texas A&M Transportation Institute, 43 participants drove vehicles on a closed course.
Motorists first completed the circuit without the distraction of a mobile phone, before doing three laps while carrying out different texting exercises - two using voice-to-text apps, Siri for the iPhone and Vlingo for Android, and one texting manually.
Researchers found response times were twice as long when drivers texted, regardless of which method they used.
Motorists spent significantly less time focusing on the road ahead when they used any of the range of texting options.
For the majority of the tasks performed in the study, the voice-to-text method took longer than manual texting but there was little change in driver performance.
The participants remarked that they felt less safe when they texted while driving, although they did feel safer when using a voice-to-text app opposed to texting manually.
Christine Yager, an associate transportation researcher who led the study, said: "Understanding the distracted driving issue is an evolving process, and this study is but one step in that process."
Copyright Press Association 2013