Researchers find how the brain decides how we listen to our mobile

While it may seem obvious that you hold your phone with your dominant hand, researchers have uncovered the brain processes which lead us to decide which side we listen on.

If you are a left-brain thinker, the chances are you use your right hand to hold your phone up to your right ear, according to the study from the Henry Ford Hospital in Detroit.

The research reveals a strong correlation between brain dominance and the ear used to listen to a phone.

More than 70 per cent of the study’s participants held their phone up to the ear on the same side as their dominant hand, the study found.

Left-brain dominant people - who account for about 95 per cent of the population and have their speech and language centre located on the left side of their brain - are more likely to use their right hand for writing and other everyday tasks.

Likewise, the Henry Ford Hospital study reveals that most left-brain dominant people also hold the phone to their right ear.

Right-brain dominant people are more likely to use their left hand to hold their phone to their left ear.

‘Our findings have several implications, especially for mapping the language centre of the brain,’ said Dr Michael Seidman, of Henry Ford Hospital.

‘By establishing a correlation between cerebral dominance and sidedness of cell phone use, it may be possible to develop a less-invasive, lower-cost option to establish the side of the brain where speech and language occurs rather than the Wada test, a procedure that injects an anaesthetic into the carotid artery to put part of the brain to sleep in order to map activity.’

He notes that the study may also offer additional evidence that mobile phone use and tumours of the brain, head and neck are not linked.

Since nearly 80 per cent of people hold their phone to their right ear, he says if there were a strong connection there would be far more people diagnosed with cancer on the right side of their brain, head and neck, the dominant side for cell phone use.

The study began with the simple observation that most people use their right hand to hold a phone to their right ear.

This practice, Dr Seidman says, is illogical since it is challenging to listen on the phone with the right ear and take notes with the right hand.

To determine if there is an association between sidedness of cell phone use and auditory or language hemispheric dominance, the Henry Ford Hospital team developed an online survey using modifications of the Edinburgh Handedness protocol, a tool used for more than 40 years to assess handedness and predict cerebral dominance.

The survey included questions about which hand was used for tasks such as writing, time spent talking on a phone, whether the right or left ear is used to listen to phone conversations, and if respondents had been diagnosed with a brain or head and neck tumour.

On average, respondents’ phone usage was 540 minutes per month. The majority of respondents, 90 per cent, were right handed, nine per cent were left handed and one per cent was ambidextrous.

Among those who are right handed, 68 per cent reported that they hold the phone to their right ear, while 25 per cent used the left ear and seven per cent used both right and left ears.

For those who are left handed, 72 per cent said they used their left ear for phone conversations, while 23 per cent used their right ear and 5 per cent had no preference.

The study also revealed that having a hearing difference can impact ear preference for phone use.

In all, the study found that there is a correlation between brain dominance and laterality of phone use, and there is a significantly higher probability of using the dominant hand side ear.