Abstract: To provide a sound collection system using a plurality of microphones arranged in the proximity to one another and having an excellent directivity for an arbitrary position in the sound field space. A plurality of control points are set around a plurality of sound collecting microphones. A desired response function matrix A (?) and a transfer function matrix C (?) between the control points and the respective microphones are measured. A control filter H arranged in a digital signal processing unit (2) is connected to each of the microphones constituting the sound collection device (1). The control filters H are arranged for the number of output channels of a reproduction unit (4). An output of each of the control filters H is added for each channel and outputted to each channel of the reproduction unit (4).

Abstract: An audio device capable of easily generating two or more sets of surround signals based on 2-channel stereo signals and a method for generating surround sound are provided. The audio device 100 includes: an SL signal generation section 20 and a BL signal generation section 40 as first surround signal generation units for receiving an L signal and an R signal as 2-channel stereo signals, extracting a component of the R signal having high correlation with the L signal, subtracting the component from the L signal, thereby generating a first surround signal; and an SR signal generation section 30 and a BR signal generation section 50 as second surround signal generation units for extracting a component of the L signal having high correlation with the R signal, subtracting the component from the R signal, thereby generating a second surround signal.

Abstract: Provided are a three-dimensional audio signal processing system using a rigid sphere and a method thereof. The three-dimensional audio signal processing system of the present research simplifies the shape of a human head into a rigid sphere, acquires three-dimensional audio signals by setting up mikes on the rigid sphere, and applies the acquire three-dimensional audio signals to diverse existing reproduction systems. The system includes a three-dimensional audio signal acquiring unit for acquiring audio signals by using a predetermined number of mikes set up on the rigid sphere; and a three-dimensional audio signal post-processing unit for converting the acquired audio signals to reproduce in diverse reproduction environments such as five-channel, four-channel, headphone, stereo, and stereo dipole reproduction environments.

Abstract: The input signal X of one channel is divided by a multi-stage delay processing device Z?1 and each of the outputs is superimposed by a specified coefficient by a coefficient processing device W0, W1, . . . , Wk. The results are added by an adder, thereby providing a correlation eliminating filter for extracting a signal component from the input signal X of one channel having a high correlation with the input signal Y of the other channel. There is provided a coefficient updating processing device 5 for successively changing the feature of the correlation eliminating filter according to an error signal e obtained from the output signal RES and the input signal Y from the other channel, and the input signal X of one channel. A surround signal is obtained from a difference between the output RES from the correlation eliminating filter and the input signal Y of the other channel.

Abstract: An audio device capable of easily generating two or more sets of surround signals based on 2-channel stereo signals and a method for generating surround sound are provided. The audio device 100 includes: an SL signal generation section 20 and a BL signal generation section 40 as first surround signal generation units for receiving an L signal and an R signal as 2-channel stereo signals, extracting a component of the R signal having high correlation with the L signal, subtracting the component from the L signal, thereby generating a first surround signal; and an SR signal generation section 30 and a BR signal generation section 50 as second surround signal generation units for extracting a component of the L signal having high correlation with the R signal, subtracting the component from the R signal, thereby generating a second surround signal.