A jury test can allow a range of different products to be tested and to determine which one sounds the best and which the worst. For instance, what might be tested is a range of products from different manufacturers in a particular price band. By identifying the best and worst products in terms of sound, it is then possible to design products which avoid the worst sounds and make the best sounds.
Manufacturers are often motivated to look at sound quality when they find complaints from customers, maybe a product is making an annoying sound or is overly noisy. The problem can be confirmed and investigated using jury testing.
Jury testing can also be used to shape the sound to some desired characteristic. For example, to make a product sound more powerful, more robust and better made.
Sound quality assessment can also use a range of metrics to compare the sound from different products. These metrics approximately represent the human response, for example the metric loudness should correspond to people's perception of how loud a product is. To find out which metrics are useful for which product, it is necessary to measure people's responses to a range of sounds from a product type, and then relate (correlate) the subject's responses to the metrics. Consequently, even if the intention in the long term is to use metrics to evaluate sound quality, in setting up the metrics, and finding out which ones are important for which products, it is necessary to undertaken jury testing.
It is also possible through jury testing to evaluate the worth of different alterations to a product to the sound produced. For example, it is possible to take a sound that a current product makes, and change this to simulate the effects of changing components in the product. By this method, it is possible to come up with the desired sound for a product before a full prototype has to be constructed.
Another approach is to develop a virtual prototype to enable predictions to be made of product sounds before physical protoypes are made. In the automobile industry, virtual protoypes are used at the early stages of the design to try and estimate what the sound quality will be like early in the design cycle, as it is easier and cheaper to alter the sound of a product if that is considered early on. Even with an existing product, simple changes can be made to the product to understand what different components are doing to change the sound quality. For example, with the kettle you could remove the lid and therefore get a sense of the effect of the air enclosure above the water .
1] ‘Designing for Product Sound Quality’ R.H. Lyon, (Marcel Dekker 2000)