An objective metric for describing the basic acoustics of binaural directivity patterns in humans

Abstract

It is accepted knowledge that having two ears are better than one when trying to listen to a signal of interest in the presence of spatially-separated noise sources (e.g. Blauert, 1997; Bregman, 1994; Zurek, 1993). Models have been proposed purporting of the benefits of the head shadow effect, binaural interactions, and cognitive factors that explain how one can understand sound with linguistic or other contextual meaning better in the presence of spatially-separate noise sources. However, less discussed is the attribute of human listeners having the ability to also hear and identify sound sources, seemingly on demand, that occur around them, a condition made possible by the fact of having two ears. Zurek (1993) proposed and discussed at length on the directivity effects of binaural listening (e.g., Better Ear Strategy). What is proposed in this study is an extension to this model to include the omni-directional directivity effects of binaural listening to describe the listener’s ability to remain connected and aware of the sound landscape that surrounds them. Where the head shadow effect plays a role in improving the signal-to-noise ratio in one of the two ears, this strategy looks at how the two ears, due to their geometric location on the head, allows for the head to be acoustically transparent and keeps the listener connected to their surrounding sound landscape.