SOUND EFFECTS

Sensory confusion

Lawrence Rosenblum, a Professor of Psychology at the University of California, Riverside, points out that sound affects our perception of our hands when we rub them together. He calls this 'the parchment skin illusion'. A high frequency sound makes most of us think our hands are dry. A lower frequency makes us think of smoothness, and that our hands, therefore, are slightly damp.

He can cite many examples of such 'multiple sense perception'. For instance, the sight of people clapping their hands together vigorously makes viewers think they're making more noise than those clapping calmly. Somebody smelling cherries while drinking plain sugared water will very likely taste cherry. And somebody presented with a dark-coloured drink will tend to think it's stronger in taste than one lighter in appearance.

Then there is the 'McGurk effect', discovered by psychologist Harry McGurk and John MacDonald in 1976, and illustrated by Rosenblum by a clip from a BBC2 programme that you can easily find on YouTube. (Search for ‘the McGurk Effect’.) What you see in the clip is a person saying ‘da'. However, if you close your eyes, what you hear them saying is 'ba'. If you open your eyes again but mute the sound, they then appear to be saying 'ga'. 

What's happening is that your brain is trying to reconcile conflicting sensory inputs - and getting confused. It illustrates the fact that all the information gathered by our senses is treated equally by our brain. We may think that our senses take leading and supporting roles - that, for instance, when listening to someone speaking our hearing is 'in charge' - but this isn't true.  Our brain doesn't need to know where the information is coming from; it has no preferences. It's only concerned with what's happening in the world around it. 

One message, multiple values

The sound of a closing car door is the most well-known, and frequently used, example of sensorial design approach. Many of the top automobile brands have separate door development teams, with design engineers and properties developers dedicated to fine-tuning their particular - signature - closing car door sound.

With the sound of their car doors, Mercedes have built two layers of value into one message. The first is the brand level; the second is a category value proposition. For example, the sound their SUV doors make when closing shares the 'standard' sound of all Mercedes' cars. However, the SUV doors have also been tuned to sound heavier, as a way of displaying their robustness. 

This may sound odd, but consider this: When you're looking for a car, it's unlikely that you'll be able to start up the engine in the showroom to listen to it. But you will be allowed to open a door and sit inside. So opening and closing its doors is one of the few things you'll actually be able to experience. As Emar Vegt, an aural designer at BMW, noted in an article in Wired magazine, 'The sound of the door closing is a remarkable aspect of the buying decision'.

Where to start?

Now, I'm not suggesting that we should focus only on the aspects of sensorial design that influence people’s buying decision. But it is a logical starting point. And it gives you the chance to evaluate people’s behaviour in the shopping environment, to understand what they are looking for in your product category. Understanding that will more than likely point you towards the areas that would most benefit the design of multi-sensorial value proposition.