NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Studying Room Acoustics using a Monopole-Dipole Microphone ArrayThe use of a soundfield microphone for examining the directional nature of a room impulse response was reported recently. By cross-correlating monopole and co-located dipole microphone signals aligned with left-right, up-down, and front-back axes, a sense of signal direction of arrival is revealed. The current study is concerned with the array's ability to detect individual reflections and directions of arrival, as a function of the cross-correlation window duration. If is window is too long, weak reflections are overlooked; if too short, spurious detections result. Guidelines are presented for setting the window width according to perceptual criteria. Formulas are presented describing the accuracy with which direction of arrival can be estimated as a function of room specifics and measurement noise. The direction of arrival of early reflections is more accurately determined than that of later reflections which are quieter and more numerous. The transition from a fairly directional sound field at the beginning of the room impulse response to a uni-directional diffuse field is examined. Finally, it is shown that measurements from additional dipole orientations can significantly improve the ability to detect reflections and estimate their directions of arrival.
Document ID
20020048135
Document Type
Conference Paper
Authors
Begault, Durand R. (San Jose State Univ. Moffett Field, CA United States)
Abel, Jonathan S. (San Jose State Univ. Moffett Field, CA United States)
Gills, Stephen R.
Date Acquired
August 20, 2013
Publication Date
January 1, 1997
Subject Category
Acoustics
Meeting Information
16th International Congress on Acoustics(Seattle, WA)
Funding Number(s)
PROJECT: RTOP 199-06-12-32
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.