The second electronic device may be a portable electronic device, such as a digital media player, that includes a voice user interface.

ENGADGET: Apple patents Siri-like system for controlling cameras, PMPs through a computer or smartphone

The National Transportation Safety Board voted 5-0 to recommend that states ban all driver use of cell phones and other portable electronic device while driving except for emergencies.

FORBES: NTSB To States: Ban All Driver Use Of Mobile Phones

The Portable People Meter is an electronic device that measures nearby radio signals.

FORBES: Magazine Article

As such, the bulk, weigh, and cost for manufacturing the second electronic device may be reduced, resulting in a more portable and affordable product.

ENGADGET: Apple patents Siri-like system for controlling cameras, PMPs through a computer or smartphone