When I was younger I worked in a supermarket warehouse and picked items into a pallet for shipping to a store with a system just like this. (Woolworths Supermar

When I was younger I worked in a supermarket warehouse and picked items into a pallet for shipping to a store with a system just like this. (Woolworths Supermarkets, Western Australia) The voice had 4 speeds, and all the experienced pickers would have it turned up to the top speed. Once you were experienced enough though, you would learn the confirm codes for the different bays, and speak though the pick to the voice system 5 steps ahead just so it didn't slow down your pick. Workers that came from a paper sheet pick list in the previous factory prefered the paper as they could memorize the pick sheet with a single reading, and thus pick faster - and if they did want to double check at the end they had the sheet in front of them to do so.