A Differential Microphone Array with Input Level Alignment, Directional Equalization and Fast Notch Adaptation for Handsfree Communication
Conference: Speech Communication - 11. ITG-Fachtagung Sprachkommunikation
09/24/2014 - 09/26/2014 at Erlangen, Deutschland
Proceedings: Speech Communication
Pages: 4Language: englishTyp: PDF
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Authors:
Geiser, Bernd; Krueger, Hauke; Vary, Peter (Institute of Communication Systems and Data Processing, RWTH Aachen University, 52056 Aachen, Germany)
Geiser, Bernd; Krueger, Hauke (Javox Solutions GmbH, Gallierstr. 33, 52074 Aachen, Germany)
Wiese, Detlef (Binauric SE, Am Soeldnermoos 17, 85399 Hallbergmoos, Germany)
Abstract:
We revisit the standard differential microphone of [1] and propose three algorithmic enhancements. First, a simple alignment procedure equalizes the power levels of the input signals. Second, we describe an efficient algorithm to equalize the distorted directional response of the original algorithm. This enables a wider operating frequency range and helps to reduce the noise gain of the array. Third, a fast time-domain notch adaptation algorithm is presented to reliably track interfering sound sources. Its tracking performance is not impaired by the activity of desired sound sources. Finally, we describe a fixed-point arithmetic implementation of the modified algorithm for wideband handsfree communication (fs =16 kHz) using two miniature digital MEMS microphone capsules.