This lecture presents an overview of signal processing for robot audition. Human-robot communication is essentially supported by speech recognition whose performance is known to be seriously degraded in adverse environment. To help a robot recognize commands given by the user, four signal processing techniques are useful, namely, direction-of-arrival (DOA) estimation, noise cancellation, echo cancellation, and beam forming. Problems in these techniques which are specific to human-robot communication are identified and solutions to those problems are presented. Video demonstrations in the talk will help audience understand effects of these techniques.