Improving the signal chain of a Doppler simulation

A recent paper described the N-Oversampled Transmitted Acoustic Pressure (NOTAP) method of auralizing moving sound sources and simulating the Doppler effect. This method eliminates possible aliasing and imaging artifacts via oversampling using the relatively simple zero-order hold interpolation heuristic (also called sample and hold). However, this oversampling approach has two main disadvantages: the generation of broadband noise and a moderate attenuation of high frequency content. Canonical strategies for dealing with these problems are not directly applicable to the NOTAP framework. This presentation explores several methods to address these problems by either extending existing strategies or proposing altogether new strategies. These include asynchronous filtering to compensate for the high-frequency losses, exploring the use of new interpolation kernels, and estimating the induced noise signal so that it can be subtracted from the final auralization. The efficacies of these strategies are discussed in terms of their computational burden and the complexity that they add to the NOTAP method.