Order pickers wear headphones and microphones attached to wireless devices. When an order is ready to be picked, the system tells the picker where to go, and what and how much to pick. The picker then speaks into the microphone, identifying the items picked and the location. This information is transmitted to the computer, which, in turn, transmits it back to the main system for verification. The picker immediately is informed of any errors. VDP systems can also be used for putaway tasks.