Title :
An adaptive close-talking microphone array
Author :
Teutsch, Heinz ; Elko, Gary W.
Author_Institution :
Telecommun. Lab., Erlangen-Nurnberg Univ., Erlangen, Germany
Abstract :
Close-talking differential microphone arrays (CTMAs) are useful in situations where the background noise level is very high because they inherently suppress farfield noise while emphasizing desired nearfield signals. One problem, however, is that the array has to be placed as close to the desired source (talker´s mouth) as possible since the frequency response and level of a differential nearfield array depend heavily on its position and orientation relative to the source signal. In order to be able to utilize the advantages of CTMAs for an extended range of microphone positions, this contribution examines the possibility of tracking the desired signal source by estimating its distance and orientation angle. Having this information, appropriate correction filters can be applied adaptively which equalize unwanted frequency response and level deviations within a reasonable range of operation without significantly degrading the noise canceling properties of differential arrays. A PC-based real-time implementation with transducer calibration capabilities of this adaptive CTMA is presented
Keywords :
acoustic arrays; acoustic noise; adaptive equalisers; adaptive filters; array signal processing; calibration; direction-of-arrival estimation; interference suppression; microphones; signal detection; speech processing; tracking; adaptive close-talking microphone array; adaptive correction filters; differential microphone arrays; differential nearfield array; distance estimation; farfield noise; high background noise level; nearfield signals; noise canceling; orientation angle estimation; signal tracking; speech signal acquisition; transducer calibration capabilities; Adaptive arrays; Adaptive equalizers; Adaptive filters; Background noise; Frequency response; Information filtering; Information filters; Microphone arrays; Mouth; Noise level;
Conference_Titel :
Applications of Signal Processing to Audio and Acoustics, 2001 IEEE Workshop on the
Conference_Location :
New Platz, NY
Print_ISBN :
0-7803-7126-7
DOI :
10.1109/ASPAA.2001.969568