Cancellation of Unwanted Audio to Support Interactive Computer Music

A real-time unwanted-audio cancellation system is developed. The system enhances recorded sound by canceling unwanted loudspeaker sounds picked up during the recording. After cancellation, the resulting sound gives an improved estimation of the live performer’s sound. The cancellation works by estimating the unwanted audio signal and subtracting it from the recorded signal. The canceller is composed of a delay block and two adaptive digital filters. Our work extends conventional echo-cancellation methods to address problems we encountered in music applications. We describe a realtime implementation in Aura and present experimental results in which the proposed canceller enhances the performance of a real-time pitch detector. The cancellation ratio is measured and limitations of the system are discussed.