In this work, the authors present a comprehensive methodology for multizone sound field reproduction using specially designed speech masking filters. The masking filters are design to maximise speech privacy and quality. Trade-offs between speech privacy and quality are shown to exist and parameters are provided in the methods to control their values. An accurate and precise formulation of grating lobes from spatial aliasing in multizone reproduction scenarios is provided and used to enhance the masking filters. The mathematical descriptions and thorough methodology are evaluated using simulations and a real world implementation of a multizone sound field reproduction.
Using a planar array of microphones and loudspeakers, the authors show in this work a theoretical approach to actively suppressing the reflection of sound from boundaries, such as room walls. The filters that are proposed are applicable to real-time implementations and it is shown that the active absorption is similar to that of passive fibre panel absorption.
Ever wondered if you could cancel someones voice without the need for a physical wall or partition? In this work presented at ICASSP 2017 in New Orleans, USA, we investigate the possibilities of cancelling speech over a loudspeaker wall. The method is not limited to speech, in-fact, it works much better for periodic signals as the non-stationarity of speech degrades the performance.
A hybrid loudspeaker system consisting of dynamic point sources and parametric loudspeaker models shows great results above, generally inevitable, soundfield aliasing frequencies.
This work was presented at APSIPA ASC 2016 in Jeju, Korea.