The 'cocktail party' effect explains a phenomenon that occurs when focusing on a single source of auditory stimuli among the multiple sources of noise. When focus is applied, everything outside the range of focus is effectively tuned out of the individual's perception. This does not mean that the brain stops processing the background stimuli. A word or phrase of importance to the individual will catch their attention and shift their focus. This effect highlights how information is filtered to our conscious or subconscious.
In 1953, Colin Cherry defined the 'cocktail party' problem. Through experiments, Colin was able to determine that separating background noise is affected by many variables such as the direction the sound is coming from, the pitch of the sound, the rate of speech, and even the sex of the speaker. The experiments Cherry conducted would have participants listening to two different messages coming from the same speaker at the same time. The listeners would then have to separate the different messages. This is now considered a dichotic listening test that is used to test selective attention. Another technique Colin developed to further study the selective hearing issue was speech shadowing. In the speech shadow testing, a participant repeats the message heard from a specific channel (left or right) which is called shadowing. When repeating the message from the shadowed channel, participants were able to detect their name coming from the channel they were not shadowing. Neville Moray also conducted speech shadowing in 1959 and was also able to show the effect of the cocktail party problem. Both Cherry and Moray could conclude that the participants only could pick up on important messages when attention was elsewhere.
While it is clear that the brain does process information that an individual is not attentively listening to, the selection process seems to limit the awareness of these background noises. After all, not every word is consciously heard, only the important messages relating to that individual will be made aware to them. The subconscious activities of the brain are responsible for this filtration. The process of how the brain decides to filter information for an individual is brings about different proposed models of attention. The 'filter model' was proposed by Donald Broadbent. Another theory of selective attention is the 'attenuation model' by Anne Treisman. Diana Deutsch who is known for her work in music perceptions and auditory illusions has also contributed towards models of attention with Don Norman. They created the 'Deutsch-Norman model' which differs from the 'attenuation model'. Daniel Kahneman has proposed his own model that describes attention in terms of capacity and not selection. He also concentrates on how attention is focused instead of when attention is focuses unlike the other models of attention. The 'Kahneman model' does not contradict the other models of attention but can instead be supplemented with them.
Despite many models of attention based on auditory stimuli, some research suggests that the 'cocktail party' phenomenon also occurs with visual information. In 1997, the University of Calgary performed four experiments to demonstrate the visual 'cocktail party' effect. The study demonstrated that the participants looking at other names were still able to detect their own name when it was presented as unattended stimuli. The exact mechanisms that cause the selective attention are still unknown. On a subconscious level the mind is filtering the information that is available to the conscious mind. There is simply too much going on in our environments to be able to focus on everything.
The 'cocktail party' effect pertains to our perception, attention, and consciousness. It suggests that there can be different levels of consciousness. It is possible to be more or less aware of sensory input even when not paying attention to it. How much do our brains process below the level of conscious awareness? We are not aware of how much we are not aware of. When people have good attention spans they tend not to experience the effect as much as people with wandering minds who lose attention quickly. Focus has a lot to do with what you are aware of. As you change your attention, you are changing what sensory information to be aware of. Everyone will experience this phenomenon to different degrees.
Author: Jordan Bonneau