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Main Authors: Linhard, Klaus, Bulling, Philipp
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2510.12377
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author Linhard, Klaus
Bulling, Philipp
author_facet Linhard, Klaus
Bulling, Philipp
contents Undesired acoustic feedback is a known issue in communication systems, such as speech in-car communication, public address systems, or hearing aids. Without additional precautions, there is a high risk that the adaptive filter - intended to cancel the feedback path - also suppresses parts of the desired signal. One solution is to decorrelate the loudspeaker and microphone signals. In this work, we combine the two decorrelation approaches frequency shifting and phase modulation in a unified framework: a so-called \textit{phase synthesizer}, implemented in a discrete Fourier transform (DFT) filter bank. Furthermore, we extend the phase modulation technique using variable delay lines, as known from vibrato and chorus effects. We demonstrate the benefits of the proposed phase synthesizer using an example from speech in-car communication, employing an adaptive frequency-domain Kalman filter. Improvements in system stability, speech quality measured by perceptual evaluation of speech quality (PESQ) are presented.
format Preprint
id arxiv_https___arxiv_org_abs_2510_12377
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A Phase Synthesizer for Decorrelation to Improve Acoustic Feedback Cancellation
Linhard, Klaus
Bulling, Philipp
Audio and Speech Processing
Undesired acoustic feedback is a known issue in communication systems, such as speech in-car communication, public address systems, or hearing aids. Without additional precautions, there is a high risk that the adaptive filter - intended to cancel the feedback path - also suppresses parts of the desired signal. One solution is to decorrelate the loudspeaker and microphone signals. In this work, we combine the two decorrelation approaches frequency shifting and phase modulation in a unified framework: a so-called \textit{phase synthesizer}, implemented in a discrete Fourier transform (DFT) filter bank. Furthermore, we extend the phase modulation technique using variable delay lines, as known from vibrato and chorus effects. We demonstrate the benefits of the proposed phase synthesizer using an example from speech in-car communication, employing an adaptive frequency-domain Kalman filter. Improvements in system stability, speech quality measured by perceptual evaluation of speech quality (PESQ) are presented.
title A Phase Synthesizer for Decorrelation to Improve Acoustic Feedback Cancellation
topic Audio and Speech Processing
url https://arxiv.org/abs/2510.12377