由ASHRAE赞助的一项早期研究表明，在确定人们对低频HVAC噪声的主观反应时，有三个因素很重要。该研究由Broner（1994）发起，主题是“确定占用空间中低频HVAC噪声与舒适度之间的关系-客观阶段”。这些不一定按重要性排序，而是总体水平、光谱不平衡以及振幅和时间调制效应。该报告还建议进行心理声学测试，以调查这些参数，目的是确定评估低频HVAC噪声的最合适的低频指标。本报告详细描述了第2阶段心理声学测试的实施和方法。测试中使用的噪声刺激来自并基于第一阶段研究中收集的测量刺激。为了评估噪声刺激的响度和烦扰度的心理属性并对其进行评分，我们使用了震级估计任务对噪声刺激进行评分。 还收集了对停止刺激和不可接受性的缓解评估。本报告详细说明了评估低频HVAC噪声的最合适低频指标的推导结果并得出结论。报告还对未来的研究工作提出了建议。

An earlier research study sponsored by ASHRAE on the "Determination of the Relationship between Low Frequency HVAC Noise and Comfort in Occupied Spaces - Objective Phase" by Broner (1994) suggested that three factors are important in determining the subjective response of people to low frequency HVAC noise. These, not necessarily in order of importance, were overall level, spectral imbalance and amplitude and temporal modulation effects. The report also recommended psycho-acoustic testing to investigate these parameters with a goal of determining the most appropriate low frequency metrics for assessment of low frequency HVAC noise.This report describes in detail the implementation and methodology used for the Phase 2 Psycho-acoustic testing. Noise stimuli for use in the testing were chosen from and based on the measured stimuli collected in the Phase 1 Study. To assess and rate the psychological attributes of loudness and annoyance of the noise stimuli, the magnitude estimation task was used to rate the noise stimuli. Assessments of relief-on-cessation of the stimuli and un-acceptability were also collected. This report details the results and draws conclusions with respect to the derivation of the most appropriate low frequency metrics for assessment of low frequency HVAC noise. The report also recommendss future research work.