Patent ID: 8284961

Claim:
A signal processing device, comprising: a generation circuit operable to generate a second signal from a first signal that is obtained by downmixing two signals; a mixing coefficient determination circuit operable to determine, based on a value L and a value θ, a mixing degree for mixing the first signal and the second signal, the value L indicating a level ratio between the two signals, and the value θ indicating a phase difference between the two signals; and a mixing circuit operable to mix the first signal and the second signal based on the mixing degree determined by the mixing coefficient determination circuit, wherein the generation circuit includes: a first filter circuit operable to generate a low frequency band signal in the second signal, from a low frequency band signal in the first signal; and a second filter circuit operable to generate a high frequency band signal in the second signal, from a high frequency band signal in the first signal, the first filter circuit is operable to generate the low frequency band signal in the second signal by, using a delay circuit and an all pass filter, (i) decorrelating a complex-number signal and (ii) adding a reverberation component to the complex-number signal, the complex-number signal being the low frequency band signal in the first signal, and the second filter circuit is different from the first filter circuit and is operable to generate the high frequency band signal in the second signal by, using an all pass filter, (i) decorrelating a real-number signal and (ii) adding a reverberation component to the real-number signal, the real-number signal being the high frequency band signal in the first signal.