ASTM E3207-21

4.1?The purpose of the LIR rating is to describe the low-frequency impact noise, often referred to as thudding, primarily generated by footfall on lightweight structures. The rating increases as the impact sound attenuation of the floor-ceiling structure increases. This rating has been shown to correlate with subjective reaction4.2?The LIIC rating can be used for relative comparison and to rank-order the low-frequency performance of assemblies within a given test laboratory.Note 1:?The tendency for measurement uncertainty to increase at low frequencies should be considered when utilizing metrics of classification standard.

4.3?This classification shall only be used with one-third-octave-band data.

1.1?This classification provides methods for calculating single-number ratings of low-frequency impact noise transmission, based on one-third-octave-band impact noise levels as described in Test Methods E492 and E1007.

1.2?This classification defines ratings that are not defined in other standards. Other standards may define additional ratings based on the methods of this classification.

1.3?UnitsThe values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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

1.5?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.