1.1 This guide covers many measurement methods and criteria for evaluating environmental noise, some of which are required to be used for specific purposes by governmental regulations. It is intended to provide users who may not be familiar with them with an overview of the wide variety of available methods and criteria. It includes the following:

1.2 Criteria Selection-Thorough evaluation of noise issues requires consideration of many characteristics of both the sound and the environment into which it is introduced. This guide will assist users in selecting criteria for the following:

1.3 Reasons for Criteria-This guide discusses the many reasons for noise criteria, ways sound can be measured and specified, and advantages and disadvantages of the most widely used types of criteria. The guide refers the user to appropriate documents for more detailed information and guidance. Users needing further general background on sound and sound measurement are directed to the books listed in the References section.

1.4 Criteria in Regulations-Certain criteria are specified to be used by government regulation, law, or ordinance for specific purposes. Any investigation or evaluation of a community noise issue must start with identifying applicable regulations and evaluating compliance with them. This document discusses but is not limited to regulations and ordinances. Due to the wide variation in local regulations, those are discussed more generally, and specific criteria are provided only from national government regulations. Regulations typically specify measurement methods and criteria for purposes of the regulation. Local ordinances must be written for ease of enforcement and cannot address all situations satisfactorily without becoming too complex. Such ordinances are also often prepared without competent guidance and can be too restrictive in some cases and not restrictive enough in others. Other regulations that determine government spending for noise control must balance that cost to the general public against impacts on individuals.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.