Web-Based Product Noise Declarations

Sound and Vibration, Jul 2004 by Nobile, Matthew A, Eames-Harlan, David

This article covers a proposed program for making standardized noise declarations for both industrial and consumer products. The proposal is aimed at the information technology industry in particular but is generally applicable to all industry groups.

Since the publication in the mid0 -0 1980s of ISO 7574 "Statistical Methods for Determining and Verifying Stated Noise Emission Values of Machinery and Equipment," steady progress has been made towards providing consumers with meaningful product noise declarations. ISO 4871 "Declaration and Verification of Noise Emission Values of Machinery and Equipment" was issued soon thereafter and translated the general provisions and technical statistics of ISO 7574 into a practical, usable method for products. The Information Technology (IT) industry became one of the first industry groups or trade associations to specialize the requirements of ISO 7574 to its own family of products. It published ISO 9296 in 1988, which tailored the declaration and verification provisions of ISO 7574 to IT product noise declarations. The primary consensus descriptor in these standards is the "declared E-weighted sound power level," L^sub WAd^. One of the authors recently presented a proposal for an industry group program that could facilitate the widespread use of product noise declarations, thus enabling consumers to make informed purchasing decisions regarding the noisiness of the products they are considering. That proposal laid the framework for organizing the industry group's Acoustics Committee and offered suggestions for dealing with the many logistical issues that would undoubtedly arise in managing such a volunteer program among competing companies. One key element ofthat proposal was the use of the worldwide web for publishing the noise declarations themselves. This article describes how web-based noise declarations might be implemented, and discusses some of the benefits of this approach. The discussion and examples are particularly geared to the IT industry, but the concepts and rationales are general enough to be applied to any industry, from consumer products to high-tech medical equipment.

Background

In 1985, a standard was published that was to have far-reaching consequences for consumers: ISO 7574, Statistical Methods for Determining and Verifying Stated Noise Emission Values of Machinery and Equipment.1 For the first time, consumers and other purchasers would be able to get noise emission information for the products they buy just as they were able to get nutritional information on food, power usage information on electrical appliances, or gas mileage information on cars. ISO 7574 was published in four parts and promulgated the benefits of declaring noise emission values while describing, in great mathematical detail, the statistical methods needed for determining and verifying the declared value. In an attempt to make the statistical requirements of ISO 7574 a bit more tractable for the manufacturers who make the declarations, ISO 4871, Declaration and Verification of Noise Emission Values of Machinery and Equipment was drafted.2 It condensed the information in ISO 7574 and assigned a value to the so-called reference standard deviation. The "statistical upper limit E-weighted sound power level" (in decibels) was the preferred quantity and was given the symbol L^sub WAd^ for "declared sound power level" (and informally pronounced 'elwahd'). In addition, a simplified procedure for verifying the declared value was specified based on a random sample of three machines. Presumably, the presence of the latter would help guarantee that the declared values would be accurate and honest and thus afford a level playing field for the consumer.

While it is true that in the two decades since its original publication ISO 4871 has been referenced extensively in national and international standards, industry test codes, and European Directives, it is safe to say that the original promise of ISO 7574 has not yet been realized. Most noise-omitting products on the market today are still being bought and sold without any noise emission information being made available to the potential purchaser. Consumers cannot walk into a Home Depot or Sears and easily find and compare the noise levels of the Toro� vs. the Weed Eater� weed wacker. They cannot sit down with their kitchen design contractor and confidently base their selection of the dishwasher, refrigerator or garbage disposal on the lower-noise offerings (or, in any event, balance noise versus price).

Product manufacturers today, as a matter of course, are determining the noise emission levels of their products, either in their own acoustics labs or through outside testing services. They are using the resulting data to ensure that their products meet specifications. They are using the data to drive engineering modifications to improve the product quality. Why are they not providing this information to the public?

To be fair, there has been some success in making product noise declarations. Consumers can actually compare bathroom exhaust fans from a noise level standpoint, thanks to the efforts of the Home Ventilating Institute (HVI). HVI member companies agreed among themselves that they would be required to label the noise emission level (in sones) of bathroom fans, range hoods, and other home ventilators when measured according to a uniform, standardized test procedure that they developed. In 1988, the Information Technology (IT) industry became the first to specialize the requirements of ISO 7574 and ISO 4871 to its own products, by drafting ISO 9296, AcousticsDeclared Noise Emission Values of Computer and Business Equipment.'' Based on the measurement test codes of the IT industry and the particular family of products common to the industry, a standard deviation of reproducibility and a reference standard deviation were defined and incorporated into the standard. The IT industry has had good success with its ISO 9296 standard on at least two fronts - (1) there is virtually unanimous support for it within the IT industry, and (2) many standards, regulations, environmental labeling documents, and company specifications refer to its requirements and procedures for declaring and verifying IT product noise emission levels. Yet in terms of the availability and accessibility of actual noise declarations for IT products, the IT industry has not had all that much success. This for an industry with its own fully-endorsed international standard giving them all the reasons for declaring, and prescribing exactly how to go about doing so. Why? The authors feel that the answer to this question, as well as the above question relating to manufacturers in general, may have nothing to do with economics or business strategy, but instead with the way manufacturers think about how to present the noise declarations to the public. If their general mindset remains that of the mid0 -0 1980s when the idea of noise declarations first appeared with ISO 7574, i.e., printbased noise declarations and all the logistical problems that come with communicating between acoustics labs and corporate publications departments, it is no wonder that published noise declarations are hard to find.