Let the Cocktail Party Effect Guide your Design
Recall the last time you were at an event with a lot of people. Perhaps you had a large gathering to celebrate Thanksgiving. Or maybe you went out for happy hour last weekend with some of your co-workers. You might have gotten coffee the other day in a busy coffee shop. Whatever it was, think back to that occasion. Think of how many people were there, how much was going on. Think of all the noise in the room. Was there music playing? Was there a game on tv? Were there a lot of conversations going on at the same time? Think really hard about what was going on at that time? Or rather, ignore all that, because that's exactly what you did that day.
Despite all that was going on, the dozens of conversation, the music in the background, the noise from the tv, whatever it was, you were able to engage in 1 on 1 or small group conversations with little or no difficulty. In short, you were able to act normal despite all that was going on around you. You were benefiting from the Cocktail Party Effect.
The Cocktail Party Effect and Design
The Cocktail Party Effect, first named by Colin Cherry, describes the ability of people to focus on auditory signals in a busy environment, essentially filtering out all other noise to hone in on one particular audio channel. A cocktail party is of course a perfect example of a situation where such an ability would be needed, hence the name.
The Cocktail Party Effect has been known for over 60 years, but it is not very well known in the design community. At first glance, it can be considered a bit of a quirk of human nature. It also doesn’t directly impact too much of product design, since it takes place in the auditory channel, which does not get too much run in design.
On deeper examination though, it is has important things to say about human capabilities. The Cocktail Party Effect results from internal mechanisms to solve a real world problem and its origins are completely understandable. We are bombarded with inputs at all times of the day. If we tried to attend to every stimulus all the time, we would not be able to function.
As designers, we need to understand this phenomenon (and others like it) and think of how we could shape our products to take advantage of what people do naturally. The Cocktail Party Effect shows that people have natural abilities to process large amounts of information in their environment and focus on the most relevant thing at the time.
Not only do we have it in our auditory channel, but we also have a similar ability in our visual channel. Our eye is split into two parts — when we focus on something, we are using our fovea. The fovea helps us see the fine details of what we are looking at. Everything else is coming in through the periphery. The periphery isn’t in high definition, but allows us to see basic shapes, motion, and contrast. When we are goal oriented we can focus on what we need to in the environment. All the while, our periphery is still taking in stimuli and providing just enough information to help us determine if we should switch our attention.
It’s up to us as designers to leverage these capabilities within our products. And there are ample opportunities to do so. We can lean on these natural human capabilities every time someone complains of data overload, for example.
We often hear talk about data overload and how people struggle when presented with too much data. But what evidence do we have that its a result of human failing? The evidence we often see is that when confronted with lots of data, people fail. Case closed, right? Well, no. This is a classic case of correlation not equaling causation.
The reason people struggle so much with large amounts of data is due to poor design. It’s not so much that people can’t handle large data sets, it’s more that we as a design community have done so poorly designing for large data sets.
We live in a busy world. Every inch of our bodies is taking in sensory input, pretty much non-stop. Thinking about it in these terms, we should be hard-pressed to overwhelm our users with too much data. The only way to do so is if we fail to design for our users. Part of being human-centered is actually understanding what capabilities people have, not just what they are trying to do. This is why learning about cognitive and perceptual psychology is so important. How can you be human-centered if you don’t know how people work?
Design Impact part 2
There is another aspect of the Cocktail Party Effect that needs to get mentioned. It is something we all have experienced. You are again engaged in a conversation in a busy crowd. Then without warning, you hear your name mentioned somewhere else in the room. You excuse yourself from your current conversation to see why you were mentioned in another conversation.
Notice what happened there? Even while you were focused, you were still able to redirect your attention to something else that was important in your environment. Your senses (in this case your auditory channel) are always working to identify important cues that require your attention. This is a survival mechanism. If primitive man was so focused on the antelope he was trying to hunt that he could not detect the lion creeping up, mankind would never have made it as a species. Our hearing and peripheral vision are always working, always collecting new information to determine if we should be focused on something else.
Consider the impact of this on the design. We already know of so many things that can distract us in our products. Banner ads are the ultimate in distraction. Alerts are not that far behind. Everyone knows this, but no one seems to know what to do about it. The problem is that people create alerts with the assumption that in a busy world, it is too easy to miss important things. So they design alerts to demand attention. But how often is the alert really worth the attention? More often than not, whatever is presented to you could wait a while or be ignored altogether.
What if alert designers took cues from our natural processes and found ways to allow people to use their natural peripheral processes to choose what they should draw attention to? We do this naturally everyday in the physical environment. We should carry this forward in our product / digital environments as well. The key is that alerts must not demand our attention but request it. They must allow the person to choose where to apply their focus. Our current activities will provide the context we need to decide whether we need to refocus. If we decide to change, great. If not, we have not shifted our focus to determine whether we need to shift focus. This is a constant waste of energy and prevents us from achieving good flow.
People are more capable than they are given credit for. The Cocktail Party Effect is a great demonstration of how capable people are when in an environment that is designed for them (technically, I guess you could say we were designed for the world before we started to design within it). When we create products, we should be trying to fit into the world that exists rather than trying to force our users to adjust to the environment that we create. We can either try to outsmart evolution, or we can take advantage of what people already do well. If we don't, we will never be truly human-centered.