Now that you 've brought the display and side buttons to the front of the Vocera badge, how bout giving them some use to the users?  Why not allow them to pull up a contacts list, either entered manually through the user console, or a list of the most recent 20 or so callers or people called?  It could be the default screen if the upper or lower buttons are pushed, and only pressing the center button initially would bring up all the menus the average person never uses.

This way, even those with heavy accents or the ones who struggle with voice recognition will have a speedy alternative to the genie interaction they have come to dread.  Want to call back the person who just called?  Press the lower button, the last caller's name is automatically highlighted on the screen.  Press the center button to select and call that person.  Press the upper button for your personal contact list.