Patients with persistent ringing in their ears - a condition known as tinnitus - process emotions differently in the brain compared to those with normal hearing, says a study.
"When you hear annoying noises constantly that you cannot control, it may affect your emotional processing systems," said Fatima Husain, speech and hearing science professor at University of Illinois in the US.
The researcher used functional magnetic resonance imaging (fMRI) brain scans to better understand how tinnitus affects the brain's ability to process emotions.
Three groups of participants were used in the study: people with mild-to-moderate hearing loss and mild tinnitus; people with mild-to-moderate hearing loss without tinnitus; and a control group of age-matched people without hearing loss or tinnitus.
Activity in the amygdala, a brain region associated with emotional processing, was lower in the tinnitus and hearing-loss patients than in people with normal hearing.
Tinnitus patients also showed more activity than normal-hearing people in two other brain regions associated with emotion, the parahippocampus and the insula.
"We thought that because people with tinnitus constantly hear a bothersome, unpleasant stimulus, they would have an even higher amount of activity in the amygdala when hearing these sounds, but it was lesser," Husain added.
The study appeared in the journal Brain Research.