本文件规定了一种实验室方法，以便于比较家具组合和外壳降低产品内部使用者说话水平的能力。 在这种方法中，声功率级是在两种情况下测量的:1）不使用产品，2）使用产品。在场景1）中，当产品不存在时，测试信号由空房间中的声源产生。在场景2）中，测试信号由位于乘员位置的产品内部的声源产生。电平降低是指在125 Hz到8000 Hz的1/1倍频程频带内，在两种情况下测得的声功率级的差异。语音级别缩减是一个单一的数字量，表示一个语音级别中相应的缩减- 在125 Hz到8000 Hz的整个频率范围内，标准语音的加权声功率级。 该方法适用于整个家具组合或外壳，这些组合或外壳形成一个整体，为一个或多个居住者提供服务，还用于改善语音隐私。 此方法不适用于工作站中使用的单个组件，例如屏幕、存储单元、桌子、灯具、橱柜、书架、标准椅子、墙壁吸收体或天花板吸收体。

This document specifies a laboratory method to facilitate the comparison of furniture ensembles and enclosures with respect to their ability to reduce the speech level of the occupant speaking inside the product. In this method, the sound power level is measured in two scenarios: 1) without the product, and 2) with the product. During scenario 1), the test signal is produced by the sound source in an empty room while the product is absent. During scenario 2), the test signal is produced by the sound source inside the product in the occupant's position. Level reduction is the difference of the sound power levels measured in the two scenarios in 1/1-octave frequency bands from 125 Hz to 8 000 Hz. Speech level reduction is a single-number quantity that expresses the corresponding reduction in A-weighted sound power level of standard speech within the entire frequency range from 125 Hz to 8 000 Hz. The method is applicable for entire furniture ensembles or enclosures, which form a unity that serves one or several occupants, and which are also used to provide improved speech privacy. This method is not intended for single components used in workstations, such as a screen, a storage unit, a table, a luminaire, a cupboard, a bookshelf, a standard chair, a wall absorber or a ceiling absorber.