| abstract |
When an audio stream signal is transmitted, the bit stream information for determining the surround mode and special-use mode, including karaoke use, is sensed from the signal at a mode sensor (163). After the surround mode has been sensed, the audio data is converted by a decoder into a front left, front center, and front right main audio signals and a back left and back right surround audio signals in the surround mode, which are converted into analog signals and outputted to the corresponding speakers (8L, 8C, 8R, 8LS, 8RS). When the special-use mode has been sensed, by using the central main audio signal of the front left, front center, and front right main audio signals and back left and back right surround audio signals converted at the decoder, a normally used first-type accompanying sound selectively made unused, for example, guide melody, is generated. In addition, by using the back left and back right surround audio signals, a normally unused second-type accompanying sound selectively used, for example, vocals, is generated. The first- and second-type accompanying sounds, together with the front left and front right main audio signals, are reproduced selectively. Consequently, a system that transmits surround sound using a plurality of channels can maintain compatibility with a surround system easily, when the plurality of channels are applied to special use, such as karaoke, not being restricted to surround use. |