No external ambient noise around the user is picked up.
2
在这段时间内,环境噪声分贝直线上升。
Over that time span, ambient noise levels went up.
3
应当避免混入很多其他交谈特性,例如咳嗽、键盘噼啪响声以及过度的电话线或环境噪声。
There are many attributes of normal human conversation that should be avoided, such as coughs, keyboard clacking, as well as excessive line or ambient noise.