| 摘要 |
<p>A surround-decoder comprises terminals (15, 16) to which left and right stereo input signals are applied, a decoder (17) for processing the left and the right stereo input signals to provide left and right stereo output signals, a center output signal and a surround output signal, circuits (18, 19, 20, 21) for detecting the left and the right stereo input signals to be monaural signals, and a switch (22) responsive to an output signal of the detecting circuit for cutting off an output of a surround signal from the decoder.</p> |
