This European Standard assigns sound insulation values to all transparent, translucent and opaque glass products, described in European Standards on basic or processed glass products, when intended to be used in glazed assemblies in buildings, and which exhibit properties of acoustic protection, either as a prime intention or as a supplementary characteristic. This document outlines the procedure, by which glass products may be rated, according to their acoustic performance which enables assessment of compliance with the acoustic requirements of buildings. Rigorous technical analysis of measurement data remains an option, but this standard is intended to enable the derivation of simpler indices of performance, which can be adopted with confidence by non-specialists. By adopting the principles of this standard, the formulation of acoustic requirements in Building Codes, and of product specification to satisfy particular needs for glazing is simplified. It is recognised that the acoustic test procedures of EN ISO 140-1 and EN ISO 140-3 relate fully only to glass panes and their combinations. Although the same principles should be followed as closely as possible, it is inevitable that some compromises are necessary, because of the bulkier construction of other glazing types. Guidelines on how to adapt these to include glass blocks, bricks, structural glazing, channel-shaped glass and pavers are offered in clause 4. NOTE Performance variation in windows. All the considerations of this standard relate to glass alone. Incorporation of them into windows may cause changes in acoustic performance, owing to other influences, including frame design, frame material, mounting method, air tightness, etc. Measurements of the sound insulation of complete windows (glass and frame) may be undertaken to resolve such issues.