Herein disclosed is a sound signal processing apparatus (10), comprising: a speaker unit (12) for converting a first sound signal to a first sound; sound signal producing means (13) for producing a second sound signal constituted by at least two different components including an echo component indicative of the sound outputted by the speaker unit (12), and a voice component indicative of one's voice having a least one leading end; echo component suppressing means (14) for suppressing the echo component of the second sound signal on the basis of the first and second sound signals to output, as a third sound signal, the suppressed second sound signal; sound signal storing means (15) for storing the third sound signal outputted by the echo component suppressing means (14); voice detecting means (16) for detecting the leading end of the speaker's voice on the basis of the third sound signal outputted by the echo component suppressing means (14); and controlling means (17) for controlling the sound signal storing means (15) to have the sound signal storing means (15) output, as a fourth sound signal, said third sound signal stored in the time period when said voice is detected on the basis of said third sound signal outputted by said echo component suppressing means, the controlling means (17) being operative to specify two different clock times on the basis of a predetermined time difference, the clock times including a first clock time at which the leading end of the voice is detected by the voice detecting means (16), and a second clock time prior to the first clock time, the controlling means (17) being operative to have the sound signal storing means (15) start to output the third sound signal stored after the second clock time.