The sound transmission loss provided by a material that covers a flat surface depends not only on the physical properties of the material but also on the type of structure to which it is mounted and the mounting method used.

Naval and marine architects and design engineers require specific transmission loss characteristics of acoustical treatment materials as they would exhibit installed on a ship's structure. The mounting structure and procedures specified in these practices are intended to simulate such a shipboard environment.

Test reports may refer to this mounting by Practices E 1123 instead of providing a detailed description of the mounting used.

1.1 These practices describe test specimen mountings to be used for naval and marine ship applications during sound transmission loss tests performed in accordance with Test Method E 90.

1.2 The structure specified in these practices is intended for mounting of single-layer treatments or composite treatments consisting of various materials and configurations. Acoustical treatment materials may be combinations of acoustical absorbent materials, limp mass septums, and insulation materials.

1.3 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.

1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.