Why backseat drivers are less trouble than a mobile phone

Why backseat drivers are less trouble than a mobile phone

The Scotsman
28 Jul 2005
SHAN ROSS

SCIENTISTS have revealed why driving and talking on a mobile phone is more distracting than carrying out a conversation with a passenger.

They found that as the car moves, the mobile phone switches continually between base stations - causing a loss of sound quality with interruptions, making the motorist's brain work harder to hear the other person. This leaves fewer auditory resources to allocate to events outside the car.

Dr Takashi Hamada, of the National Institute of Advanced Industrial Science and Technology in Tokyo, measured the sound quality of phone calls in parked cars and in cars travelling at 65kph (40mph).

A comparison of the two revealed silent periods of about 300 milliseconds, interrupting the signal roughly six times a minute, according to a report in New Scientist.

They also discovered a time lag of about 300 milliseconds for a phone in a moving car - while for 5 per cent of the time the frequency range becomes distorted.

The researchers then played volunteers an audio recording of a story that included similar interruptions.

As they struggled to hear the distorted parts of the recording, their right parietal cortex - the part of the brain that perceives sound - became more active.

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