It can also be used to smooth out clicks or other extraneous impulse noises from source material. (Please be advised that sampling sounds from albums and CDs is normally a copyright infringement, and ...It can also be used to smooth out clicks or other extraneous impulse noises from source material. (Please be advised that sampling sounds from albums and CDs is normally a copyright infringement, and as such, is against the law. In order to draw with the pencil, the wave must be magnified to the point where it is no longer filled in. If you move from right to left, the pencil will erase the preceding wave segment, so that you can redraw over the segment without releasing the mouse button.