Disclosed is a method for speech processing, an information device, and a computer program product. The method for speech processing, as implemented by a computer, includes: obtaining a mixed speech signal via a microphone, wherein the mixed speech signal includes a plurality of speech signals uttered by a plurality of unspecified speakers at the same time; generating a set of simulated speech signals according to the mixed speech signal by using a Generative Adversarial Network (GAN), in order to simulate the plurality of speech signals; determining the number of the simulated speech signals in order to estimate the number of the speakers in the surroundings and providing the number as an input of an information application.