According to another embodiment of the invention, given that there can be an activity sensor proximate to a user's ear or head, the activity sensor can be utilized to control an electronic device (e.g., electronic device 216). For example, if the electronic device is a mobile media playback device, then the movement of the user's head can be utilized to invoke commands for the media playback device. For example, moving one's head in a predetermined manner can be considered as a gesture. In the case of the media playback device such a gesture can cause play, pause, next, back, skip, volume up, or the volume down.

To simplify user input gestures and/or processing therefore, a gesture can be combined with a user input action (e.g., button action). For example, if a cord for headphones, earbuds or headsets include a user input device (e.g., user input device 126), the user input device 126 (e.g., button) can be activated (e.g., pressed) while (or immediately prior or immediately after) the gesture is being performed. This allows the device to understand when it receives a gesture intended to cause a user control of some feature of the electronic device.

More generally, gestures, such as head gestures, can be used as inputs to an electronic device. Sensors (e.g., accelerometer, gyroscope, motion sensor) provided proximate the user's ear or head can be used to detect, pitch, roll and/or yaw of the head, all of which can be potentially used as inputs to an electronic device. The head gestures can have various meanings depending on application. For example, the same head gesture can initiate a different action in different applications. The sensing used to identify a gesture can be binary or analog. For example, with regards to binary, a head turn may simply change from one state to another. With regards to analog, the movement itself may impact a control function. It should be appreciated that head gestures may be used separately or in combination to provide inputs. The various motions that may be detected include, for example: left tilt, right tilt, back and forth left and right tilt, forward tilt, back tilt, back and forth forward and back tilt, left rotation, right rotation, back and forth right and left rotation, swirling the head in a circle in vertical orientation, swirling the head in a circular manner in a horizontal orientation. The motions may also be distinguished or altered as a function of speed, time, pauses in between, etc. An entire head gesture language may be developed. In one example, a head bobbing can be used in a manner similar to Morse code in order to provide text input commands. Further, "noise" filtering can be provided so as to reduce erroneous detection of gestures during regular head movements. The various gestures can cause inputs (e.g., commands) to an electronic device, such as for an application operating on the electronic device. The inputs can be user selections, user data inputs, scroll, browse, navigation, cursor control, etc.

In one implementation, a scroll, browse or paging action can be initiated or controlled by one or more head gestures. For example, a rotate head or tilt head to right can cause a next item/page action to the right. Subsequently holding ones head in the tilted position can cause the speed of the action to increase until head returns to normal position.

In another implementation, a yes/no input can be provided by a head gesture. For example, if system asks a user of a mobile telephone for input when the mobile telephone is in use, such as when another call comes in, the user can be prompted with a screen that asks whether to skip an incoming call or place current call on hold to answer incoming call. In response, the user could simply reply yes or no as he would in normal conversation. Alternatively, the user could provide one or more head gestures, e.g., back and forth horizontal head movement for a "no" response or back and forth vertical head movement for a "yes" response.

In another implementation, an up or down movement creates vertical scroll event, whereas left or right movement creates horizontal scroll event, and further holding ones head in up, down, left or right position can increase or accelerate the rate of scrolling until the head is moved back to normal.

In another implementation, a head gesture can be used to acknowledge something. For example, a simple head tilt, may be used as an enter command.

In another implementation, moving the head left can request a "forward: action, and moving the head right can request a "back" action, or vice versa, Alternatively, moving the head upward in the vertical direction can request a "back" action, and moving the head downward in the vertical direction can request a "forward" action.

The Monitoring System  

Apple's patent FIG. 2 is a block diagram of an electronic system 200 according to one embodiment of the invention. The electronic system includes a monitoring system 202 that monitors physical conditions, such as activity, associated with a user of the electronic system. The monitoring system can include at least one sensor that captures monitored data.