1. An apparatus for generating a speech signal, the apparatus comprising: microphone receivers for receiving microphone signals from a plurality of microphones; a comparator arranged to, for each microphone signal, determine a speech similarity indication indicative of a similarity between the microphone signal and non-reverberant speech, the comparator being arranged to determine the similarity indication in response to a comparison of at least one property derived from the microphone signal to at least one reference property for non-reverberant speech; and a generator for generating the speech signal by combining the microphone signals in response to the similarity indications, wherein the comparator is further arranged to determine the similarity indication for a first microphone signal in response to a comparison of at least one property derived from the microphone signal to reference properties for speech samples of a set of non-reverberant speech samples.