Dissertation – Product Sounds: Fundamentals & Application

During my PhD, I investigated perception of and design for product sounds. Product sounds are those we hear when driving cars, making coffee, clicking a computer mouse. These sounds may have psychological consequences on people during product use and often need to be designed in order to evoke a desired experience. I investigated how simple auditory experiences derive from complex cognitive functions and to what extent the perception of sound is dependent on the context in which sound is represented. My studies included auditory categorization, sound labelling, memory function, ambiguity in identification, and effect of context.

Did I made you curious? Below is the summary of my thesis and you can download the full thesis here.

Products are ubiquitous, so are the sounds emitted by products. Product sounds seem to influence our reasoning, emotional state, purchase decisions, preference, and expectations regarding the product and the product’s performance. Thus, auditory experience elicited by product sounds may not be just about the act of hearing or a sensory response to an acoustical stimulus (e.g., this is a loud and sharp sound). People actually experience a product sound beyond its acoustical composition. People hear what the sound represents and appraise the product accordingly; or, they see what the product represents and appraise the sound accordingly.

Existing studies on product sounds mostly focused on the acoustic and engineering qualities of the sound in relation to the product and disregarded the human contribution to the experiential aspects of the sound. Determining the psychoacoustical reaction to a sound has been the next step engineers took to determine people’s preference for certain sounds. In summary, our knowledge on product sounds is limited. A new approach, focusing on the psychological aspects of product sounds, is necessary to discover the meaning people derive from or attach to product sounds.

Understanding the human aspect of product sounds does not only concern the potential buyers or users. Ultimately, designers will benefit from this new approach. They will be able to predict the psychological consequences of their decisions and will be supported in their conceptual thinking regarding sounds. This new approach will provide a proper vocabulary that describes product sounds, and ultimately a systematic methodology to design sounds. Obviously, a gap exists between the fundamentals of product sound experience and application of product sound design. This thesis bridges this gap by providing empirical findings and pointing out their relevance to the practice of product sound design.

Our knowledge about the world consists of concepts. In memory, these concepts consist of perceptual and semantic information concerning an object. Thus, seeing, hearing, feeling a product, interacting with it, or a being in a certain location will activate a bundle of relevant information that is glued by concepts. It seems impossible to isolate meanings attached to sounds from the influence of other product properties. Therefore, in this thesis product sounds are investigated through the concept of a product.

Similarly, early experiments (Chapters 1 and 2) investigate the concepts product sounds are represented with. First, basic sounds categories are determined based on the perceptual similarities of different product sounds. Accordingly, people can distinguish six categories of sounds: air, alarm, cyclic, liquid, impact, and mechanical. Each of these sound categories can be represented with various concepts in memory. Our studies suggest that eleven different types of basic concepts exist: action, emotion, location, material, abstract meanings, onomatopoeia, psychoacoustics, sound type, source, source properties, and temporal descriptions. These findings are the first to suggest that listeners’ responses to product sounds are based on experiential aspects of sounds and not only on acoustical aspects. These experiential aspects also often relate to the product that emits the sound.

Considering the occurring product sound concepts, it is evident that it is often the product that dominates the mental representation of product sounds. To investigate this further, people’s memory performances concerning product sounds are tested with accompanying pictures or text that described the product as sound source (Chapter 3). Interesting findings are that the presence of a picture or a label at learning a sound allows people remember the label of the sound. However, the presence of an image at learning a sound hinders the recognition performance. This suggests that source of the sound has a positive semantic influence on memory for product sounds, but negative influence on storing the sound’s auditory properties (spectral-temporal).

As suggested by the first experiments, meaning attribution to product sounds occur on different levels of semantic association. The most commonly occurring sound description has been the ‘source’ description. That is, when people are asked to describe what they hear, their direct response would be labeling the sound by the product name. Despite their effort to label the product, people are not very good at providing the right label for the sound if the sound is presented without context (Chapters 4 and 5). Incorrect responses often refer to a very similar product sound (e.g., hand-dryer instead of hairdryer). This makes product sounds ambiguous. However, the presence of context helps people to correctly label a sound (Chapter 5). The context may be a room in which the product sound often occurs (e.g., bedroom) or an object that is conceptually related to the product (e.g., hairbrush). The latter context provides the most information for the correct identification of the sound source.

In conclusion, these experimental findings altogether provide more insight into the mental representations of product sounds and demonstrate that responses given to product sounds depend on the type of the sound, availability of the context, and the use of interaction with the sound. Another important finding is that sound is an integral property of the product. Consequently, meaningful associations conveyed by a sound are subject to influences of the product concept. Furthermore, the ambiguity of the product sounds provides bases for the conceptual judgments. That is, a product sound may not be correctly identified as, e.g., a hairdryer. Yet, this sound will activate other concepts. Listeners use meanings derived from concepts to judge the congruency between a product and its sound.

The remaining part of the thesis mainly tackles designers’ activities regarding product sounds. Because product sound design is a very new topic, (sound) designers lack tools and methods to design product sounds more efficiently. Therefore, a new visual tool that can facilitate the communication of sound designers during a design activity is proposed (Chapter 6). This tool makes use of pictograms that visually depict a composition of a product sound. Thus, a library of pictograms is designed to represent certain sound producing parts. With the sound producing parts and their physical representations on the computer, designers can model product sounds in the conceptual design phase.
In addition, the existing methods of product development are reviewed and a new methodology for designing product sounds is proposed (Chapter 7). Especially, sounding sketches and sounding models need to be included in a designer’s daily routine of sound design. The proposed method enables (sound) designers to systematically tackle the sound design process and to efficiently communicate the sound related design problems/solutions.

Finally, the disciplines (acoustics, engineering, psychology, psychoacoustics, and musicology) contributing to product sound design are discussed and the responsibilities of a sound designer within the multi-disciplinary task of sound design are indicated (Chapter 8). It is suggested that product sound design should be an independent field that encompasses an inter-disciplinary approach. Therefore, design teams should include an expert who understands the inter-disciplinary nature of product sound design.

With this thesis, I hope to draw attention of both industry and academia to product sound design as an upcoming discipline. The thesis focuses on the human-aspect of product sounds. Findings demonstrate that the effects product sounds have on people are undeniable. Therefore, these effects should be considered at all times for the design, marketing, selling, and the use of the product.