The noise restrictions are based on measurements on animals in captivity exposed to noise levels that induce a temporary threshold shift (TTS) in hearing. The TTS onset threshold is the lowest noise exposure capable of inducing a small temporary reduction of hearing sensitivity, also known as auditory fatigue, with full recovery shortly after exposure.
噪音限制是基于对圈养动物的测量，这些动物暴露在噪音水平下，导致听力暂时阈值移位（TTS）。TTS的起始阈值是最低的噪声暴露，能够引起短暂的听力敏感性下降，也称为听觉疲劳，在暴露后不久就完全恢复。
