Brain helps us turn deaf ear to spouse

Middle-aged people are very effective at blocking out their husband or wife's voice in order to hear a stranger more clearly. Photo / Thinkstock

Middle-aged couples are able to tune out each other's voices selectively so that they can pay more attention to other people, a study suggests.

Husbands and wives become so familiar with one another's pitch and sound that they become more simple to separate from background noise.

While this makes it easier to focus on each other's voices, for example when having a conversation on a noisy train, it also makes it easier to "tune out".

However, the ability to ignore your partner declines with age as older people find it harder to listen to one voice at the expense of another, the study found.

Researchers from Queen's University in Canada said that familiar voices, such as those of a spouse, affect the way an "auditory scene" is organised in the mind of a listener.

The team asked married couples aged 44 to 79 to record themselves reading out scripted conversations; each participant then listened to the tape of their spouse's voice while hearing a recording of a stranger at the same time.

The volunteers were asked to report what either their spouse or the other person had said, to determine whether familiar voices would be easier to distinguish.

The results, published in the journal Psychological Science, showed that participants of all ages were able to distinguish their spouse's voice much more clearly than an unfamiliar voice.

It also showed that middle-aged people were very effective at blocking out their husband or wife's voice in order to hear a stranger more clearly.

They were more able to tune in to an unfamiliar voice when it was played alongside their spouse's voice than when it was played alongside that of a stranger.

Dr Ingrid Johnsrude, who led the study, said: "The middle-aged adults were able to use what they knew about the familiar voice to perceptually separate and ignore it, so as to hear the unfamiliar voice better.

"The benefit of familiarity is very large. It's in the order of the benefit you see when trying to perceptually distinguish two sounds that come from different locations compared to sounds that come from the same location."

Participants lost this ability as they aged, with older participants less able to hear unfamiliar voices, she said.