Characterization of talker radiation pattern using a microphone array

A microphone array has the capability of capturing the properties of a significant portion of a talker´s radiation pattern. In this paper, potential implications of measuring the radiation pattern of a talker for the recognition and enhancement of speech are discussed. Current applications of microphone arrays entail their installation in small enclosures such as a conference room or an automobile, typically placing a talker in the array´s near field. Fitting a nominal acoustic model to a sparse sampling of the radiation pattern yields parameter estimates which should prove useful as features for speech recognition. Parameter-estimation results using fixed-radius sources (loudspeakers) are presented. Other considerations unique to placement of a talker in close proximity to an array are discussed