Abstract: Two or more quiet vehicles traveling together sense each other and communicate to each other the condition of the respective drivers of the vehicles and announce their presence to pedestrians and other motorists using noise sounds. The characteristics of the emitted sounds are selected according to a level of threat presented by the quiet vehicles.

Abstract: Two or more quiet vehicles traveling together sense each other and communicate to each other the condition of the respective drivers of the vehicles and announce their presence to pedestrians and other motorists using noise sounds. The characteristics of the emitted sounds are selected according to a level of threat presented by the quiet vehicles.

Abstract: The presence of an electrically-powered quiet vehicle is accomplished by determining a state of mind or physical state of the driver, determining the presence and proximity of humans and other objects, how the vehicle is being operated and generating a noise correlative to the threat posed by the vehicle to humans and other objects.

Abstract: Two or more quiet vehicles traveling together sense each other and communicate to each other the condition of the respective drivers of the vehicles and announce their presence to pedestrians and other motorists using noise sounds. The characteristics of the emitted sounds are selected according to a level of threat presented by the quiet vehicles.

Abstract: Two or more quiet vehicles traveling together sense each other and communicate to each other the condition of the respective drivers of the vehicles and announce their presence to pedestrians and other motorists using noise sounds. The characteristics of the emitted sounds are selected according to a level of threat presented by the quiet vehicles.

Abstract: The presence of an electrically-powered quiet vehicle is accomplished by determining a state of mind or physical state of the driver, determining the presence and proximity of humans and other objects, how the vehicle is being operated and generating a noise correlative to the threat posed by the vehicle to humans and other objects.

Abstract: A communication system (100) includes a first communication device (102) having full-duplex and half-duplex capability and a second communication device (104) having half-duplex capability. The second communication device (104) recognizes that the first communication device supports a half-duplex mode of operation and automatically establishes a half-duplex audio link (116) in response thereto. System (100) provides battery savings to the devices within the system that would otherwise default into a full-duplex mode of operation.

Abstract: An earpiece device (300) provides automatic left/right ear sensing for stereo reception as well as the ability to receive two separate and distinct channel signals. The earpiece device (300) provides an orientation indication as to which ear or channel it is coupled. A pair of such devices can be used as stereo headphones providing interchangeability between ears. The devices can also be used to receive distinct and separate channel signals. Thus, a communication system can automatically adjust a transmission to the headphone device in response to the orientation of the earpieces with minimal effort on the part of the user.