Those drivers are wrong, according to a study from the Texas Transportation Institute at Texas A&M University.
The study compared drivers using voice-to-text to those using touchscreen typing.
"In each case, drivers took about twice as long to react as they did when they weren't texting," study author Christine Yager said. "Eye contact to the roadway decreased no matter which texting method was used."
The research studied 43 drivers on a closed course. They drove the course three times: once without texting, once with dictation from either Siri for iPhone or Vlingo for Android, and once texting manually on a touchscreen.
Drivers using voice-to-text actually took longer to send messages, as they had to correct mistakes made by the voice-to-text software before sending the message.
"Every day, new technologies come out," Yager said. "It is important to educate the public that even these seemingly new distractions are still distractions, and it will help people be safer when they get into the vehicle."