To provide a sound effect circuit providing sound effects close to natural sounds.

The sound effect circuit includes low-pass filters 11 and 12 which attenuate high-frequency components of an L signal and an R signal, and an adding circuit 14 and a subtracting circuit 17 which generate the sum signal and difference signal of output signals of the low-pass filters 11 and 12. The sum signal is delayed by a delay circuit 19 and the difference signal is delayed by a delay circuit 20. A synthesizing section 30 synthesizes the L signal, the sum signal, the delayed sum signal and the delayed difference signal and outputs the synthesized signal. The synthesizing section 30 also synthesizes the R signal, the difference signal, the delayed sum signal and the delayed difference signal and outputs the synthesized signal. Delay amounts of the delay circuit 19 and 20 correspond to a time difference between sounds reaching both ears, so that sound effects can be obtained which are nearly natural and give a feeling of spreading.