Abstract: A method and apparatus for envelope detection are disclosed. An envelope detection method according to an embodiment of the invention can include: receiving ultrasonic signals reflected off a target object; detecting peaks by using differences in pulses in the received signals; and generating an envelope by connecting the detected peaks with straight or curved lines.

Abstract: Undesired variations in a signal are removed by initializing two boundaries comprising an upper boundary and a lower boundary to track the signal level. At least one of the upper boundary and the lower boundary is adjusted encapsulate/track the received signal between the two boundaries when the signal level is outside of the two boundaries. A value computed with reference to at least one of the boundaries is provided as a filter output. As a result, the output comprises desired variations that cross the boundaries and the undesired variations that are within the boundaries are eliminated. In one embodiment, an altimeter sensor signal is filtered such that the undesired variations due to noise and instability of the altimeter are removed and the desired variations representing the change in the altitude are detected and provided without any delay to the navigation subsystem.

Abstract: A method and an apparatus for outputting a sound corresponding to a musical instrument which is input by using a voice are provided. The method includes identifying a sound including an original sound, identifying an output sound object corresponding to an acoustic characteristic of the original sound, and outputting the output sound object, corresponding to musical characteristics of the original sound. Further, various aspects are provided which are related to the method and the apparatus which enable inputting sounds of a musical instrument using a voice.

Abstract: An emphasize system for an electronic musical instrument including filter and control device. The filter extract and output predetermined frequency range component of an input musical tone signal. The control device control the level of an output from the filter at least on the basis of an output from an envelope generator which controls the level of the input musical tone signal, or on the basis of the level of another frequency range component of the input musical tone signal. At least the level controlled signal is outputted from the system.