Abstract: An apparatus and method of reproducing a virtual sound of two channels which adaptively reproduces a 2-channel stereo sound signal reproduced through a recording medium such as DVD, CD, or MP3 player etc., based on a listener's position. The method includes sensing a listener's position and recognizing distance and angle information about the listener's position, determining output gain values and delay values of two speakers based on the distance and angle information about the sensed listener's position and selecting localization filter coefficients in a predetermined table, and updating filter coefficients of a localization filter based on the selected localization filter coefficients and adjusting output levels and time delays of the two speakers from the determined gain values and delay values.

Abstract: A stereo sound generation apparatus and method of reproducing multi-channel sound input signals through two-channel speakers.

Abstract: A method and apparatus to reproduce sound using a mono speaker, and a stereo sound system employing the same. The sound reproducing method can include: adding a first channel signal and a second channel signal of an input stereo signal or an input mono signal; sound field filtering by adding a sound field effect to the added signals; convolving the signal of the first channel with a first HRTF in a first convolution process; convolving the signal of the second channel with a second HRTF in a second convolution process; and adding the signal output from the sound field filtering and the signals output from the first and second convolution processes to produce an output signal.

Abstract: An apparatus and method for canceling crosstalk between 2-channel speakers and two ears of a listener in a stereo sound generation system. The crosstalk canceling apparatus includes a first signal processing unit to cross-mix first and second channel signals with gain and delay-adjusted first and second channel signals, a second signal processing unit to adjust frequency characteristics of the signals mixed in the first signal processing unit.

Abstract: A wide mono sound reproducing method and apparatus to widen mono sound by using 2 channel speakers. The method include separating an input mono sound signal into a plurality of decorrelated signals, generating virtual sound sources by localizing each of the separated signals at virtual locations asymmetrical about a center of a front side of a listening point by applying different head related transfer functions to the separated signals, and canceling crosstalk of the generated virtual sound sources.

Abstract: A method of compensating audio frequency response characteristics of a portable sound system can be performed using acoustic characteristics of a user measured in real-time. The method of compensating the audio frequency response characteristics can be used by a portable sound system. The method includes generating an acoustic characteristics curve of a user based on a minimum perception level of a user with respect to audible audio frequency bandwidths, generating an acoustic compensation curve of the user based on the acoustic characteristics curve of the user and a predetermined frequency characteristics target curve, and compensating the audio frequency response characteristics of a sound based on the acoustic compensation curve of the user.

Abstract: An apparatus to process m-channel audio input signals to produce n channel output signals, and n is less than m. This apparatus includes a first filter unit to reduce a correlation between at least two channel audio input signals among the m-channel audio input signals, a virtual sound source generation unit to transform the at least two channel audio input signals output from the first filter unit into virtual sound sources at predetermined positions around a listener position, and an output controller to control channel audio input signals other than the at least two channel audio input signals among the m-channel audio input signals based on gains and delays of the at least two channel audio input signal output from the virtual sound source generation unit. Even when the m-channel audio input signals are reproduced through 2 channels, a surround effect provided by an m-channel speaker system can be obtained. In addition, a localization of a sound is improved, and a presence is formed.

Abstract: A method of reproducing a virtual sound and an apparatus to reproduce a 2-channel virtual sound from a 5.1 channel (or 7.1 channel or more) sound using a two-channel speaker system. The method includes: generating a 2-channel virtual sound from a multi-channel sound, sensing a listener position with respect to two speakers, generating a listener position compensation value by calculating output levels and time delays of the two speakers with respect to the sensed listener position, and compensating output values of the generated 2-channel virtual sound based on the listener position compensation value.

Abstract: A method and an apparatus to reproduce a localized virtual sound source at a position in a 3-D space using multiple channel speakers. The method includes determining position information about the virtual sound source and N speakers, selecting three speakers surrounding the virtual sound source from among the N speakers by calculating N relative angles between the virtual sound source and the N speakers according to the determined position information of the virtual sound source and the N speakers, calculating gains of the selected three speakers and delay values based on distances between each of the selected three speakers, and determining output power values of the N speakers based on the calculated gains and delay values of the respective three speakers.

Abstract: A method and an apparatus to reproduce a 7.1 channel encoded sound through a 5.1 channel speaker system are provided. The apparatus includes a decoder to separate a 7.

Abstract: An apparatus and a method of reproducing a wide stereo sound by widening a stereo sound output by an audio reproducing apparatus using only two closely disposed channel speakers include a widening filtering operation and a direct filtering operation. In the widening filtering operation, virtual sound sources for arbitrary locations are formed from a stereo-channel audio signal using head related transfer functions measured at predetermined locations, and crosstalk is cancelled from the virtual sound sources using filter coefficients in which the head related transfer functions are reflected. In the direct filtering operation, signal characteristics of the stereo-channel audio signal are adjusted based on the crosstalk-cancelled virtual sound sources.

Abstract: An apparatus and a method of reproducing a wide stereo sound by widening a stereo sound output by an audio reproducing apparatus using only two closely disposed channel speakers include a widening filtering operation and a direct filtering operation. In the widening filtering operation, virtual sound sources for arbitrary locations are formed from a stereo-channel audio signal using head related transfer functions measured at predetermined locations, and crosstalk is cancelled from the virtual sound sources using filter coefficients in which the head related transfer functions are reflected. In the direct filtering operation, signal characteristics of the stereo-channel audio signal are adjusted based on the crosstalk-cancelled virtual sound sources.

Abstract: A charge pump device for supplying a boosted voltage to a memory device includes a charge pump part constructed with first to nth unit charge pumps, and a multi-level detector for detecting a level of a boosted voltage to selectively drive the unit charge pumps in accordance with an amount of power consumption of the host and thereby outputting at least one level detection signal.

Abstract: A sense amplifier circuit for a semiconductor device which can reduce current consumption by reducing the operation time of a pull-up driver for supplying the power voltage to a sense amp when a power voltage is higher than a reference voltage, and which can improve operation properties by increasing the operation time of the pull-up driver when the power voltage is lower than the reference voltage. The sense amplifier circuit includes: a first and a second pull-up drivers; a first and a second pull-down drivers; a voltage detecting unit; and selecting driver unit for respectively controlling operations of the first and the second pull-up drivers and the first and the second pull-down drivers according to the output signal of the voltage detecting unit.

Abstract: A charge pump device for supplying a step-up voltage to a host, includes: a charge pump part constructed with first to nth unit charge pumps, and a multi-level detector for detecting a level of a step-up voltage to selectively drive the unit charge pumps in accordance with an amount of power consumption of the host and thereby outputting at least one level detection signal.

Abstract: The present invention discloses a sense amplifier circuit for a semiconductor device which can reduce current consumption when a power voltage is high, and which can improve an operation property of a sense amp when the power voltage is low, by adjusting a pull-up bias voltage and a pull-down bias voltage of the sense amp according to a magnitude of the power voltage.