They completed these attention-requiring tasks while the researchers randomly played a recording of a two-person dialogue, a one-person monologue or a halfalogue. Researchers controlled the volume and told the participants to ignore the sounds and just concentrate on the assignment. At other times, no recording was played and the tasks were done in silence. The researchers found that performance was lowest — as determined by missed responses, incorrect hits and other mistakes — when the halfalogues were being played.

As I noted in this post on curiosity, we are especially drawn to gaps in information. (This is known as the "information gap" theory of curiosity, and was first described by George Loewenstein in the early 90s.) In this new study, the Cornell psychologists build on the "information gap" model. They demonstrated, for instance, that subjects listening to only one side of a conversation — what they call a "halfalogue" — showed decreased performance on a range of cognitive tasks that require undivided attention.

"We have less control to move away our attention from half a conversation (or halfalogue) than when listening to a dialogue," said Lauren Emberson, a co-author of the study that will be published in the journal Psychological Science. "Since halfalogues really are more distracting and you can't tune them out, this could explain why people are irritated," she said in an interview.