Yes they can,and yes ,it is.
It's like this: the reversers will open ,like you open the door of your car.Then you select more power from the engine (more noise) as you wish,like you'll stuck your foot out from the car to stop ,as hard as you wish (like Fred and Barney did,in Flinstones).
Try to compare the noise with the runway length-usually the shorter the rwy,the noisier the reverser is.
Brgds...