A speaker apparatus, comprising: a sound emitting section that includes a plurality of speaker units (2L, 2R), each of which converting a supplied audio signal to a sound and outputting the sound, and the speaker units (2L, 2R) including a first speaker unit for a left channel and a second speaker unit for a right channel; characterized by a monaural inputting section to which a monaural audio signal indicating a sound from a sounding body is supplied; a stereo inputting section to which at least a left channel of a stereo audio signal and a right channel of a stereo audio signal are supplied; a stereo effect imparting section that performs a first signal processing for imparting an acoustic image of stereo effect, on the monaural audio signal supplied to the monaural inputting section to output a first left channel audio signal, a first right channel audio signal, a second left channel audio signal, and a second right channel audio signal; a widening effect imparting section that performs a second signal processing for imparting a sound image widening effect as an effect of widening the range where the sound image is localizable, wherein when the first speaker unit and the second speaker unit emit sound to the front side of the speaker apparatus, while the stereo effect imparting section performs the first signal processing and while the widening effect imparting section performs the second signal processing, the listener is caused to sense as if sounds are emitted from a first virtual speaker unit and a second virtual speaker unit at respective positions which are widened to those of the first speaker unit and of the second speaker unit respectively, and the sound image widening effect is achieved by applying crosstalk cancelling as the second signal processing for imparting the sound image widening effect on the second left channel audio signal and the second right channel audio signal output from the stereo effect imparting section that performs the first signal processing for imparting the acoustic image of stereo effect and on the audio signal of the left channel and the audio signal of the right channel supplied from the stereo inputting section, to supply a processed left channel audio signal and a processed right channel audio signal; a first combining section that combines the first left channel audio signal and the first processed left channel audio signal and outputs a first audio signal; a second combining section that combines the first right channel audio signal and the first processed right channel audio signal and outputs a second audio signal; and an outputting section (21L, 22L, 21R, 22R) that outputs the first audio signal to the first speaker unit and that outputs the second audio signal to the second speaker unit. a sound emitting section that includes a plurality of speaker units (2L, 2R), each of which converting a supplied audio signal to a sound and outputting the sound, and the speaker units (2L, 2R) including a first speaker unit for a left channel and a second speaker unit for a right channel; characterized by a monaural inputting section to which a monaural audio signal indicating a sound from a sounding body is supplied; a stereo inputting section to which at least a left channel of a stereo audio signal and a right channel of a stereo audio signal are supplied; a stereo effect imparting section that performs a first signal processing for imparting an acoustic image of stereo effect, on the monaural audio signal supplied to the monaural inputting section to output a first left channel audio signal, a first right channel audio signal, a second left channel audio signal, and a second right channel audio signal; a widening effect imparting section that performs a second signal processing for imparting a sound image widening effect as an effect of widening the range where the sound image is localizable, wherein when the first speaker unit and the second speaker unit emit sound to the front side of the speaker apparatus, while the stereo effect imparting section performs the first signal processing and while the widening effect imparting section performs the second signal processing, the listener is caused to sense as if sounds are emitted from a first virtual speaker unit and a second virtual speaker unit at respective positions which are widened to those of the first speaker unit and of the second speaker unit respectively, and the sound image widening effect is achieved by applying crosstalk cancelling as the second signal processing for imparting the sound image widening effect on the second left channel audio signal and the second right channel audio signal output from the stereo effect imparting section that performs the first signal processing for imparting the acoustic image of stereo effect and on the audio signal of the left channel and the audio signal of the right channel supplied from the stereo inputting section, to supply a processed left channel audio signal and a processed right channel audio signal; a first combining section that combines the first left channel audio signal and the first processed left channel audio signal and outputs a first audio signal; a second combining section that combines the first right channel audio signal and the first processed right channel audio signal and outputs a second audio signal; and an outputting section (21L, 22L, 21R, 22R) that outputs the first audio signal to the first speaker unit and that outputs the second audio signal to the second speaker unit.