Simplification of ISO 3744 - Making the Most Important Standard for Determination of Sound Power Levels Easier to Use

Abstract

Sound power level (L_W) is the key quantity to describe the noise emission of products and is needed to reduce noise at work, at home, and in the environment, e.g. for promoting and selecting low noise products (Sell and Buy Quiet). ISO 3744:2010 is the main standard referred to by most product test codes and regulatory requirements for determining L_W. It is used by laboratories, noise control engineers, and manufacturers. Due to its structure and length, the usability of the current document is limited. The main body of ISO 3744:2010 contains so much information that the basic concept of sound power is obscured. To improve usability of ISO 3744:2010 three projects were launched: 1. A revision and restructuring of ISO 3744 with a simplified main body and a series of annexes for special cases; 2. A new standard: ISO/CD 5114-1 on the uncertainty of L_W determined from sound pressure levels; 3. A new standard: ISO/CD 26101-2 to determine the environmental correction used in determining L_W. These new standards contain specific information needed by some users while ISO/CD 3744 focusses on determining L_W. We present key aspects of all three committee drafts and explain how and why ISO 3744 should be revised.