Methods and apparatus for managing content may include receiving feedback information for content associated with a device having a set of device characteristics. Users of the system selectively specify voice message transmission instructions for controlling transmission of voice messages directed to them. A first SOC estimating unit estimates first SOC by current integration using the battery current data. The body is soft and is shaped to conform to the ear canal of the user. 264, the LCU-aligned slice for HEVC does not provide enough granularities for dividing video frames. The update data set comprises operators describing differences between two data sets, so that a remote terminal is able to transform an old data set into a more recent data set.