1.   By twisting a few knobs, technicians can add rainstorms, oncoming tankers and a shifting floor.

2.   Energy Department workers seldom, if ever, hold a shovel or a hammer or twist a knob in a control room.

3.   In a lesser car, you might simply twist a knob.

4.   Relatively simple devices that were once controlled by twisting a knob or pushing a button are now endowed with digital commands that can take hours to master.

5.   So Vizthum twisted some knobs on a computer console, and the voice improved.