A speech signal processing system comprises an audio processor (103) for providing a first signal representing an acoustic speech signal of a speaker. An EMG processor (109) provides a second signal which represents an electromyographic signal for the speaker captured simultaneously with the acoustic speech signal. A speech processor (105) is arranged to process the first signal in response to the second signal to generate a modified speech signal. The processing may for example be a beam forming, noise compensation, or speech encoding. Improved speech processing may be achieved in particular in an acoustically noisy environment.