Speakeasy: How do we selectively attend to sounds?
Imagine you’re at a classy cocktail party. The room is noisy: there’s a band playing and everyone around you is talking loudly. Yet you have no problem blocking out all of this background sound in order to pay attention to the conversation you’re having.
But what if somebody on the other side of the room mentions your name? Suddenly your attention is diverted. Even though the other conversations have just been background ‘noise’ up until now, your name stands out among all the other sounds.
This phenomenon, known as the ‘cocktail party effect’ was first demonstrated in a classic study by Cherry in 1953. Participants listened to two different messages (recorded by the same voice) presented to both ears simultaneously. They were asked to pay attention to just the information presented to one ear and ignore the other messages. Participants found it relatively straightforward to report back what was said in the ear they were paying attention to. However, they could report almost nothing from the stream they were told to ignore. They failed to notice if the speech was reversed, and even failed to notice if it switched to German!
Subsequent studies found that only very few things could be detected in the ‘ignored’ stream of auditory input. This included the participants’ name, taboo words such as swear words, and a change in the gender of the speaker. This suggests that particularly significant words may need less perceptual information to trigger recognition.
A recent study showed how context influences attention, specifically how familiar a voice is. Johnsrude and colleagues found that participants could selectively attend to their spouse’s voice better than to a stranger’s. Interestingly, it was also found that they could selectively ignore their spouses’ voice in order to attend to another voice, better than they could ignore a stranger’s voice.
These findings have many real life applications, not all of them confined to cocktail parties. For example, the finding that context plays a role in attention has important implications for people who are hard of hearing. Selective attention is a fundamental aspect of the way in which the brain works and tells us a lot about how we are able to prioritise and concentrate on the task at hand.
A good short demonstration of the effect http://www.bbc.co.uk/programmes/p00rx2zt