A number of countries are already in the process of formulating their own standards for the control and reduction of classroom noise.
一些国家已经在着手制定本国关于控制和减少教室噪音的标准。
2
The noise was quite disruptive at first, but after about four minutes the subjects were doing just as well on their tasks as control subjects who were not exposed to noise.
起初，受试者会被噪音扰乱，但大约四分钟后，他们在任务中的表现与未受噪音影响的对照组受试者一样好。
3
If the individual knows that he or she can control the noise, this seems to eliminate both its negative effects at the time and its after-effects.