Engineering product sounds to strengthen brand communication

Published on: 11th October 2018

Our opinions of products are based on more than what meets the eye. At a sensory level, it is also about the way a product sounds, feels, smells and sometimes even tastes. These elements all work together to create a product experience, and one of these sensory elements could either enhance the consumer’s experience or destroy it. At DCA, our expertise in psychoacoustics - the scientific study of sound perception - allows us to deliver products that both please the users’ ears and reflect a client’s brand.  
 
The importance of product sound

Every day we interact with products that make sounds. The definite click of a button, the authentic shutter sound of a camera and the tsssss of an aerosol. All of these sounds tell us something about a product. At the most basic level, the sound may tell us that a product is working as expected. However, it can also communicate a perceived quality or an alignment of values to a given brand.

When consumers first see a product they have certain expectations of how that product might feel, sound, smell or taste. This expectation is based on their experience of using similar products, the visual form of the product, the material it is made from or the brand it is associated with. If the product matches a user’s expectations, it typically fails to leave a lasting impression – falling into what we often refer to as the zone of indifference. However, if there is a mismatch the user is left surprised. This surprise can either be good or bad.

The sound of a car door closing is a classic example of how sensory elements of a product can reflect the desired characteristics to the consumer. If you close the doors of two cars, one of which costs significantly more than the other, you can tell which the more expensive car is just by listening to it. This is because users can perceive expressive or personality characteristics about a product through the way it sounds. In this case, if a car door were to sound robust and solid, it could lead a consumer to have high expectations of the car’s driving characteristics. Alternatively, if the car door sounded flimsy, it could lead the consumer to attach negative connotations to the car as a whole.

 

 
A rigorous approach to psychoacoustics

At DCA, we design products every day that give the consumer aural feedback. This could be the result of natural feedback, such as mechanical parts interacting with each other or artificial feedback, such as an electronic product that is programmed to make sounds. The psychoacoustic experiences of these products are not created by chance.  They are engineered from specialist knowledge of acoustics, careful consideration of user needs and understanding of brand language. Psychoacoustics is a unique challenge, largely because it requires input from the diverse disciplines of design research, human factors, mechanical engineering and industrial design, as well as increasingly electronics and software. As a multidisciplinary consultancy, we have developed a complete process for engineering psychoacoustic experiences into products.

Firstly, we work with clients to define the desired psychoacoustic experience of a product. This might be an insulin pen that has a precise and robust click when dialled or a virtual assistant in a car that has a young and sporty personality. The desired psychoacoustic experience is defined through discussing with a client how they want to represent their brand through the aural language of a product. It also requires a careful consideration of the specific users, the tasks they will be using the product to complete and the environment that it will be used in.

Our industrial designers and engineers use this defined psychoacoustic experience when generating design concepts. We take an agile approach to developing concepts, mocking up prototypes and testing them as we go. Our engineering and research teams work in parallel to evaluate the psychoacoustic experience of the product and generate evidence-based recommendations on how to improve it.  

When developing the sound of a product we use our semi-anechoic chamber to record reliable and repeatable product sounds using a binaural microphone. This interesting piece of equipment uses a pair of microphones fitted within an artificial ear structure, allowing stereo recording of the sound reaching the ear drum and producing an accurate replication of the aural experience of using the product. These recordings allow consistency between what consumers hear during testing and the sounds the engineers analyse.  

 

 

Our design research team use these recorded sounds to conduct subjective testing with consumers and evaluate the prototypes. Trying to qualitatively describe the sound of a product is difficult for the average consumer, which is why we have developed an approach to help consumers express how they feel about a sensory experience. DCA’s approach to subjective psychoacoustic testing involves a combination of breaking down the psychoacoustic experience into multiple sound attributes, ensuring we use descriptive language that is meaningful to non-technical persons, and putting consumers in a realistic context of use during testing. Throughout testing we might receive feedback such as, ‘this hair dryer sounds unexpectedly loud’, ‘the pen sounds like it might break’ or ‘this voice is too serious’.  Using our approach we are able to pinpoint which exact attributes of the sound are giving consumers this impression and then co-create ways to improve it.  

The real challenge of this process is translating verbal feedback into design recommendations for the next stage of development. Without a robust process, it is difficult to imagine bridging the gap between subjective comments about a psychoacoustic experience and quantitative technical requirements for design changes. Our process involves bringing together the qualitative and quantitative data by using a multivariable statistical regression technique to look for statistically significant correlations. It is by doing this that we may discover a correlation between quantitative and qualitative measures; for example, the pitch of a hair dryer and the consumers’ perception of power. This final step gives us clear direction for which components of a prototype we need to develop to reach the desired psychoacoustic experience.  

 

Written by Charlotte Pyatt-Downes, Design Researcher, Sophie Sladen, Mechanical Engineer, Steve Wright, Mechanical Engineer