A generalized approach to the sensing of orthogonal functions, to the global error (potential energy) for a source radiating into an enclosure is presented. The developed orthogonal functions are generalized, as they are fundamentally acoustic based and thus not constrained to being structural or written in terms of structural measurements. Therefore application can be made to any noise source, facilitating wide practical implementation of the technique. The presented acoustic-centric technique for the sensing and control of enclosure noise, by being based on the fundamental acoustic radiation shape-the monopole, thus overcoming the need for any information of the noise source (other than its approximate size) in the construction of orthogonal functions contributing to the noise within the enclosure. The presented approach then makes a significant improvement over previous work in the area of orthogonal developments for radiation into enclosures, which has typically taken a vibration-centric approach postulating vibration domain measurements to construct the global performance criterion. Therefore providing the hope of moving beyond small-scale laboratory implementations to more practical problems. Simulations are completed to illustrate the validity of the novel approach by illustrating that a controller minimizing the generalized orthogonal functions will achieve the maximum possible attenuation of the global error.