Why overhearing cellphone conversations is annoying

It's OK. You're not being unreasonably grumpy when you become irritated by a nearby cellphone conversation. A new study shows why the ever-present cellphone conversations going on around us — in the grocery store, mall, airport, elevator, on the bus, etc. — feel so intrusive.

Cellphones have made phone conversations ubiquitous. But many people confess to feeling a bit startled, then irritated, when they hear speech, think someone is talking to them and then realize the person nearby is talking to someone else on the phone. It turns out that our brains just don't like this phenomenon. Researchers at Cornell University conducted a series of tests to gauge people's reactions when exposed to four background noise settings: silence, a monologue, a conversation between two people and half a conversation (called a halfalogue). The study participants were seated at computers and asked to perform various cognitive tests while exposed to one of the three sounds or silence.

The study showed that hearing the halfalogue was the only background noise that distracted the study participants and lowered their scores on the cognitive tests. For some reason, our brains are unable to tune out half a conversation. Researchers believe this is because we can't predict the speech pattern of a halfalogue the way we can with a monologue or two-way conversation — making it harder to ignore.

Besides the mere annoyance factor, halfalogues can result in impaired performance in some settings, such as in a car. "These results suggest that a driver's attention can be impaired by a passenger's cellphone conversation," the authors wrote.

The study also provides more evidence that we understand speech, in part, by anticipating what someone will say.

"We believe this finding helps reveal how we understand language in conversation," the lead author of the study, Lauren Emberson, said in a news release. "We actively predict what the person is going to say next and this reduces the difficulty of language comprehension."

The study will be published in an upcoming issue of the journal Psychological Science.