Eating popcorn in the cinema may be irritating not just for fellow movie goers, but for advertisers: a group of researchers from Cologne University has concluded that chewing makes us immune to film advertising.

The reason why adverts manage to imprint brand names on our brains is that our lips and the tongue automatically simulate the pronunciation of a new name when we first hear it. Every time we re-encounter the name, our mouth subconsciously practises its pronunciation.

However, according to the study published in the Journal of Consumer Psychology, this "inner speech" can be disturbed by chewing, rendering the repetition effect redundant.

For their experiment, the researchers invited a group of 96 people to a cinema to watch a movie preceded by a series of adverts. Half of the participants were given free popcorn throughout the session, the other half only received a small sugar cube which immediately dissolved in their mouths.

A test at the end of the screening showed that the adverts had left no effect on those viewers who had chewed their way through popcorn throughout, while the other participants showed positive psychological responses to the products they had encountered in the ads.

"The mundane activity of eating popcorn made participants immune to the pervasive effects of advertising," said Sascha Topolinski, one of the researchers.

He goes as far as implying that his research may spell the end of the traditional popcorn machine in cinema foyers. "This finding suggests that selling candy in cinemas actually undermines advertising effects, which contradicts present marketing strategies. In the future, when promoting a novel brand, advertising clients might consider trying to prevent candy being sold before the main movie."

• This article was amended on Monday 14 October 2013 to correct minor errors that crept in during the editing process.