Design Guidelines for Device Accessories
4/8/2010
Mobile device accessories extend functionality and usefulness of mobile devices.
Headphones
Any external headphone devices such as ear buds, etc should fit securely and comfortably and not fall out of the ears easily. Hands–free microphones which are included with ear buds should be placed in a location to maximize their effectiveness. In some cases, securing the cable to clothing can aid and assist in keeping headphones or ear buds in place.
Integrated controls such as Send\End and Volume should be tactilely identifiable and differentiated from each other. Tactile identifiers such as shape, size and texture differences should be used to contrast and identify different control functions.
Headphone cables are difficult to manage without tangling, so cord and cable management solutions should be considered as these add value to the a good user experience.
Headphones and ear buds should be usable in either ear and therefore should be either reversible or have no asymmetry in their design.
Charger/AC Power Units
Consider features that assist in managing excess cable. The charger or AC power unit should be able to be easily stored and used with the cable shortened to lengths that vary from minimum to maximum.
Wall outlets are often in short supply, and power strips as well as wall outlets have specific forms. Charger industrial design should take these forms into account, allowing other chargers and device cords access to adjacent outlets without covering them. It is frustrating to users if device chargers cannot be used without having to unplug other power cords.
Many chargers accept varied input voltages but few have flexible or interchangeable prongs for different wall socket standards around the world. Consider adding this feature to the charger for greatest flexibility. When it is correctly executed, it can also reduce SKUs of chargers required for international outlet differences.