effective perceived noise level

例句：

1. 1. The engineers have designed a system that can effectively reduce the noise level in the factory.
   工程师们设计了一个系统，可以有效地降低工厂的噪声水平。
2. 2.The new hearing aids are designed to provide an effective perceived noise level reduction for people with hearing loss.
   新的助听器被设计用来为有听力损失的人提供有效的感知噪声水平减少。
3. 3. In urban areas, the effective perceived noise level is often higher due to the high levels of traffic and construction noise.
   在城市地区，由于交通和建筑噪声的水平较高，有效感知噪声水平通常更高。