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Product designers debate utility of sound quality metrics.
Traditionally, acoustic design has concentrated on reducing the noise made by excessively noisy products. But today, more companies are looking beyond mere noise control by trying to produce sounds that portray a particular image for a product, for instance, sounds which make the product appear to be well made and of high quality. Sound quality design is commonplace in the automobile industry, but less used by appliance designers. Yet, as the automobile industry has found, good sound design is one way that a product can be made to stand out, especially in a crowded, mature marketplace.
Sound quality assessment is about how to measure and assess the sound produced by a product. It is possible to use juries of customers to listen to and judge the sound produced, but because everyone is an individual, it is necessary to test many people to get some form of average response. So, jury testing is a"," rather slow and tedious method. For this reason, people have developed sound quality metrics which are meant to directly relate to human subjective response and can be measured quickly on specialist instrumentation.
For instance, there is a metric called loudness, which (unsurprisingly) relates to a person's perception of the loudness of a product. The loudness metric is more effective at modelling the human response than the better known sound pressure level measured in decibels, as it is based on a more complex model of human hearing. However, the sound quality community is split as to the usefulness of many of the sound quality metrics. Some use the metrics widely in product design, while others claim that they are useless and rely solely on jury testing.
There is a wide range of tools available advertising the ability to quantify sound quality objectively. Companies who sell sound quality hardware and software include: OldB (dBFA32), B&K (PULSE analyzer), and HEAD acoustics (Artemis and SQ lab II). These systems calculate a bewildering array of sound quality metrics. For each product type, however, only a small number of these metrics will be useful. There is one metric, though that everyone would agree is useful, and works for most products, and that is Ioudness.
The graph in Fig....