Preparing an effective noise specification - proposal for a standard

摘要

A specification for noise emission may come as part of the development of an overall technical specification for a new item or whole process plant, as a part of the assessment of compliance with a specification for a completed item, or similar. Purchasers sometimes have an idea of what noise emission they want to achieve, although it may be inadequately based, being too high or too low. Suppliers want to know what they have to achieve. Acousticians are called upon to verify performance. Too often acousticians are called in at completion when it is too late to influence selection of the required sound level, to find the specification cannot to be used to verify compliance, or the sound levels requested are irrelevant to the application. Some standards, codes or guidelines include references to "Buy Quiet" procedures and similar, while others give guidance on how to design for low noise. Few documents are available to help prepare a specification that is effective - one that clearly sets the sound levels to be achieved and the basis for those, where and how they are to be measured, includes measurement tolerances and reporting requirements. The right time in the Project cycle for setting the specification is also important. This paper discusses these aspects, identifies shortcomings in specifications often seen in acousticians' war stories, and provides recommended approaches to developing effective specifications for noise, which can be included in overall technical specifications or other similar documents. A standard based guideline or procedure is proposed.