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Marc Moonen - One of the best experts on this subject based on the ideXlab platform.

  • binaural noise cue preservation in a binaural noise reduction system with a remote Microphone Signal
    IEEE Transactions on Audio Speech and Language Processing, 2016
    Co-Authors: Joseph Szurley, Alexander Bertrand, Bas Van Dijk, Marc Moonen
    Abstract:

    A general binaural noise reduction system is considered that employs the multichannel Wiener filter with partial noise estimation ( $\text{MWF}_\eta$ ) allowing for an explicit tradeoff between noise reduction and binaural noise cue preservation. In this paper, it is assumed that along with the general binaural system, a remote Microphone Signal with a high input Signal-to-noise ratio (SNR) is available for inclusion in the $\text{MWF}_\eta$ . The use of this remote Microphone Signal with a high input SNR allows for a simultaneous increase in both noise reduction performance and preservation of the binaural noise cues. To further increase the performance, a modification to the partial noise estimation (PNE) variable, $\eta$ , is proposed which relies on exploiting the aforementioned trade-off by either constraining the output SNR or binaural noise cues to the same level before and after the addition of the remote Microphone Signal. The validity of the theoretical results are supplemented via simulations using a binaural setup with a single speech and noise source.

  • improved prediction error filters for adaptive feedback cancellation in hearing aids
    Signal Processing, 2013
    Co-Authors: Kim Ngo, Toon Van Waterschoot, Marc Moonen, Mads Graesboll Christensen, Soren Holdt Jensen
    Abstract:

    Acoustic feedback is a well-known problem in hearing aids, caused by the undesired acoustic coupling between the hearing aid loudspeaker and Microphone. Acoustic feedback produces annoying howling sounds and limits the maximum achievable hearing aid amplification. This paper is focused on adaptive feedback cancellation (AFC) where the goal is to adaptively model the acoustic feedback path and estimate the feedback Signal, which is then subtracted from the Microphone Signal. The main problem in identifying the acoustic feedback path model is the correlation between the near-end Signal and the loudspeaker Signal caused by the closed Signal loop, in particular when the near-end Signal is spectrally colored as is the case for a speech Signal. This paper adopts a prediction-error method (PEM)-based approach to AFC, which is based on the use of decorrelating prediction error filters (PEFs). We propose a number of improved PEF designs that are inspired by harmonic sinusoidal modeling and pitch prediction of speech Signals. The resulting PEM-based AFC algorithms are evaluated in terms of the maximum stable gain (MSG), filter misadjustment, and computational complexity. Simulation results for a hearing aid scenario indicate an improvement up to 5-7dB in MSG and up to 6-8dB in terms of filter misadjustment.

  • prediction error method based adaptive feedback cancellation in hearing aids using pitch estimation
    European Signal Processing Conference, 2010
    Co-Authors: Kim Ngo, Toon Van Waterschoot, Marc Moonen, Mads Grosboll Christensen, Soren Holdt Jensen, Jan Wouters
    Abstract:

    Acoustic feedback is a well-known problem in hearing aids, which is caused by the undesired acoustic coupling between the loudspeaker and the Microphone. The goal of adaptive feedback cancellation (AFC) is to adaptively model the feedback path and estimate the feedback Signal, which is then subtracted from the Microphone Signal. The main problem in identifying the feedback path model is the correlation between the near-end Signal and the loudspeaker Signal, which is caused by the closed Signal loop. In this paper, a novel prediction-error-method (PEM)-based AFC is presented using a harmonic sinusoidal near-end Signal model. Furthermore, the prediction error filter (PEF) is designed to incorporate a variable order and a variable amplitude next to a variable pitch. Simulation results for a hearing aid scenario indicate an improvement up to 6dB in maximum stable gain increase and up to 8dB improvement in terms of misadjustment.

  • adaptive feedback cancellation in hearing aids using a sinusoidal near end Signal model
    International Conference on Acoustics Speech and Signal Processing, 2010
    Co-Authors: Kim Ngo, Toon Van Waterschoot, Marc Moonen, Soren Holdt Jensen, Mads Graesboll Christensen, Jan Wouters
    Abstract:

    Acoustic feedback is a well-known problem in hearing aids, which is caused by the undesired acoustic coupling between the loudspeaker and the Microphone. Acoustic feedback limits the maximum amplification that can be used in the hearing aid without making it unstable. The goal of adaptive feedback cancellation (AFC) is to adaptively model the feedback path and estimate the feedback Signal, which is then subtracted from the Microphone Signal. The main problem in identifying the feedback path model is the correlation between the near-end Signal and the loudspeaker Signal, which is caused by the closed Signal loop. A possible solution to this problem is to use the prediction error method (PEM)-based AFC with a linear prediction (LP) model for the near-end Signal. In this paper, a modification to the PEM-based AFC is presented where the LP model is replaced by a sinusoidal near-end Signal model. More specifically, it is shown that using frequency estimation techniques to estimate the sinusoidal near-end Signal model improves the performance of the PEM-based AFC compared to using a LP model. Simulation results for a hearing aid scenario indicate a significant improvement in terms of misadjustment and maximum stable gain increase.

  • speech enhancement with multichannel wiener filter techniques in multiMicrophone binaural hearing aids
    Journal of the Acoustical Society of America, 2009
    Co-Authors: Tim Van Den Bogaert, Simon Doclo, Jan Wouters, Marc Moonen
    Abstract:

    This paper evaluates speech enhancement in binaural multiMicrophone hearing aids by noise reduction algorithms based on the multichannel Wiener filter (MWF) and the MWF with partial noise estimate (MWF-N). Both algorithms are specifically developed to combine noise reduction with the preservation of binaural cues. Objective and perceptual evaluations were performed with different speech-in-multitalker-babble configurations in two different acoustic environments. The main conclusions are as follows: (a) A bilateral MWF with perfect voice activity detection equals or outperforms a bilateral adaptive directional Microphone in terms of speech enhancement while preserving the binaural cues of the speech component. (b) A significant gain in speech enhancement is found when transmitting one contralateral Microphone Signal to the MWF active at the ipsilateral hearing aid. Adding a second contralateral Microphone showed a significant improvement during the objective evaluations but not in the subset of scenarios t...

Akira Yabe - One of the best experts on this subject based on the ideXlab platform.

  • investigation of excimer laser ablation threshold of polymers using a Microphone
    Applied Surface Science, 2002
    Co-Authors: Jorg Kruger, Hiroyuki Niino, Akira Yabe
    Abstract:

    Abstract KrF excimer laser ablation of polyethylene terephthalate (PET), polyimide (PI) and polycarbonate (PC) in air was studied by an in situ monitoring technique using a Microphone. The Microphone Signal generated by a short acoustic pulse represented the etch rate of laser ablation depending on the laser fluence, i.e., the ablation “strength”. From a linear relationship between the Microphone output voltage and the laser fluence, the single-pulse ablation thresholds were found to be 30 mJ cm −2 for PET, 37 mJ cm −2 for PI and 51 mJ cm −2 for PC (20-pulses threshold). The ablation thresholds of PET and PI were not influenced by the number of pulses per spot, while PC showed an incubation phenomenon. A Microphone technique provides a simple method to determine the excimer laser ablation threshold of polymer films.

  • investigation of excimer laser ablation threshold of polymers using a Microphone
    Applied Surface Science, 2002
    Co-Authors: Jorg Kruger, Hiroyuki Niino, Akira Yabe
    Abstract:

    Abstract KrF excimer laser ablation of polyethylene terephthalate (PET), polyimide (PI) and polycarbonate (PC) in air was studied by an in situ monitoring technique using a Microphone. The Microphone Signal generated by a short acoustic pulse represented the etch rate of laser ablation depending on the laser fluence, i.e., the ablation “strength”. From a linear relationship between the Microphone output voltage and the laser fluence, the single-pulse ablation thresholds were found to be 30 mJ cm −2 for PET, 37 mJ cm −2 for PI and 51 mJ cm −2 for PC (20-pulses threshold). The ablation thresholds of PET and PI were not influenced by the number of pulses per spot, while PC showed an incubation phenomenon. A Microphone technique provides a simple method to determine the excimer laser ablation threshold of polymer films.

Jan Wouters - One of the best experts on this subject based on the ideXlab platform.

  • prediction error method based adaptive feedback cancellation in hearing aids using pitch estimation
    European Signal Processing Conference, 2010
    Co-Authors: Kim Ngo, Toon Van Waterschoot, Marc Moonen, Mads Grosboll Christensen, Soren Holdt Jensen, Jan Wouters
    Abstract:

    Acoustic feedback is a well-known problem in hearing aids, which is caused by the undesired acoustic coupling between the loudspeaker and the Microphone. The goal of adaptive feedback cancellation (AFC) is to adaptively model the feedback path and estimate the feedback Signal, which is then subtracted from the Microphone Signal. The main problem in identifying the feedback path model is the correlation between the near-end Signal and the loudspeaker Signal, which is caused by the closed Signal loop. In this paper, a novel prediction-error-method (PEM)-based AFC is presented using a harmonic sinusoidal near-end Signal model. Furthermore, the prediction error filter (PEF) is designed to incorporate a variable order and a variable amplitude next to a variable pitch. Simulation results for a hearing aid scenario indicate an improvement up to 6dB in maximum stable gain increase and up to 8dB improvement in terms of misadjustment.

  • adaptive feedback cancellation in hearing aids using a sinusoidal near end Signal model
    International Conference on Acoustics Speech and Signal Processing, 2010
    Co-Authors: Kim Ngo, Toon Van Waterschoot, Marc Moonen, Soren Holdt Jensen, Mads Graesboll Christensen, Jan Wouters
    Abstract:

    Acoustic feedback is a well-known problem in hearing aids, which is caused by the undesired acoustic coupling between the loudspeaker and the Microphone. Acoustic feedback limits the maximum amplification that can be used in the hearing aid without making it unstable. The goal of adaptive feedback cancellation (AFC) is to adaptively model the feedback path and estimate the feedback Signal, which is then subtracted from the Microphone Signal. The main problem in identifying the feedback path model is the correlation between the near-end Signal and the loudspeaker Signal, which is caused by the closed Signal loop. A possible solution to this problem is to use the prediction error method (PEM)-based AFC with a linear prediction (LP) model for the near-end Signal. In this paper, a modification to the PEM-based AFC is presented where the LP model is replaced by a sinusoidal near-end Signal model. More specifically, it is shown that using frequency estimation techniques to estimate the sinusoidal near-end Signal model improves the performance of the PEM-based AFC compared to using a LP model. Simulation results for a hearing aid scenario indicate a significant improvement in terms of misadjustment and maximum stable gain increase.

  • speech enhancement with multichannel wiener filter techniques in multiMicrophone binaural hearing aids
    Journal of the Acoustical Society of America, 2009
    Co-Authors: Tim Van Den Bogaert, Simon Doclo, Jan Wouters, Marc Moonen
    Abstract:

    This paper evaluates speech enhancement in binaural multiMicrophone hearing aids by noise reduction algorithms based on the multichannel Wiener filter (MWF) and the MWF with partial noise estimate (MWF-N). Both algorithms are specifically developed to combine noise reduction with the preservation of binaural cues. Objective and perceptual evaluations were performed with different speech-in-multitalker-babble configurations in two different acoustic environments. The main conclusions are as follows: (a) A bilateral MWF with perfect voice activity detection equals or outperforms a bilateral adaptive directional Microphone in terms of speech enhancement while preserving the binaural cues of the speech component. (b) A significant gain in speech enhancement is found when transmitting one contralateral Microphone Signal to the MWF active at the ipsilateral hearing aid. Adding a second contralateral Microphone showed a significant improvement during the objective evaluations but not in the subset of scenarios t...

  • speech enhancement with multichannel wiener filter techniques in multiMicrophone binaural hearing aids
    Journal of the Acoustical Society of America, 2009
    Co-Authors: Tim Van Den Bogaert, Simon Doclo, Jan Wouters, Marc Moonen
    Abstract:

    This paper evaluates speech enhancement in binaural multiMicrophone hearing aids by noise reduction algorithms based on the multichannel Wiener filter (MWF) and the MWF with partial noise estimate (MWF-N). Both algorithms are specifically developed to combine noise reduction with the preservation of binaural cues. Objective and perceptual evaluations were performed with different speech-in-multitalker-babble configurations in two different acoustic environments. The main conclusions are as follows: (a) A bilateral MWF with perfect voice activity detection equals or outperforms a bilateral adaptive directional Microphone in terms of speech enhancement while preserving the binaural cues of the speech component. (b) A significant gain in speech enhancement is found when transmitting one contralateral Microphone Signal to the MWF active at the ipsilateral hearing aid. Adding a second contralateral Microphone showed a significant improvement during the objective evaluations but not in the subset of scenarios tested during the perceptual evaluations. (c) Adding the partial noise estimate to the MWF, done to improve the spatial awareness of the hearing aid user, reduces the amount of speech enhancement in a limited way. In some conditions the MWF-N even outperformed the MWF possibly due to an improved spatial release from masking.

Jorg Kruger - One of the best experts on this subject based on the ideXlab platform.

  • investigation of excimer laser ablation threshold of polymers using a Microphone
    Applied Surface Science, 2002
    Co-Authors: Jorg Kruger, Hiroyuki Niino, Akira Yabe
    Abstract:

    Abstract KrF excimer laser ablation of polyethylene terephthalate (PET), polyimide (PI) and polycarbonate (PC) in air was studied by an in situ monitoring technique using a Microphone. The Microphone Signal generated by a short acoustic pulse represented the etch rate of laser ablation depending on the laser fluence, i.e., the ablation “strength”. From a linear relationship between the Microphone output voltage and the laser fluence, the single-pulse ablation thresholds were found to be 30 mJ cm −2 for PET, 37 mJ cm −2 for PI and 51 mJ cm −2 for PC (20-pulses threshold). The ablation thresholds of PET and PI were not influenced by the number of pulses per spot, while PC showed an incubation phenomenon. A Microphone technique provides a simple method to determine the excimer laser ablation threshold of polymer films.

  • investigation of excimer laser ablation threshold of polymers using a Microphone
    Applied Surface Science, 2002
    Co-Authors: Jorg Kruger, Hiroyuki Niino, Akira Yabe
    Abstract:

    Abstract KrF excimer laser ablation of polyethylene terephthalate (PET), polyimide (PI) and polycarbonate (PC) in air was studied by an in situ monitoring technique using a Microphone. The Microphone Signal generated by a short acoustic pulse represented the etch rate of laser ablation depending on the laser fluence, i.e., the ablation “strength”. From a linear relationship between the Microphone output voltage and the laser fluence, the single-pulse ablation thresholds were found to be 30 mJ cm −2 for PET, 37 mJ cm −2 for PI and 51 mJ cm −2 for PC (20-pulses threshold). The ablation thresholds of PET and PI were not influenced by the number of pulses per spot, while PC showed an incubation phenomenon. A Microphone technique provides a simple method to determine the excimer laser ablation threshold of polymer films.

Simon Doclo - One of the best experts on this subject based on the ideXlab platform.

  • relative transfer function estimation exploiting spatially separated Microphones in a diffuse noise field
    International Workshop on Acoustic Signal Enhancement, 2018
    Co-Authors: Nico Gobling, Simon Doclo
    Abstract:

    Many multi-Microphone speech enhancement algorithms require the relative transfer function (RTF) vector of the desired speech source, relating the acoustic transfer functions of all array Microphones to a reference Microphone. In this paper, we propose a computationally efficient method to estimate the RTF vector in a diffuse noise field, which requires an additional Microphone that is spatially separated from the Microphone array, such that the spatial coherence between the noise components in the Microphone array Signals and the additional Microphone Signal is low. Assuming this spatial coherence to be zero, we show that an unbiased estimate of the RTF vector can be obtained. Based on real-world recordings experimental results show that the proposed RTF estimator outperforms state-of-the-art estimators using only the Microphone array Signals in terms of estimation accuracy and noise reduction performance.

  • rtf based binaural mvdr beamformer exploiting an external Microphone in a diffuse noise field
    arXiv: Audio and Speech Processing, 2018
    Co-Authors: Nico Gosling, Simon Doclo
    Abstract:

    Besides suppressing all undesired sound sources, an important objective of a binaural noise reduction algorithm for hearing devices is the preservation of the binaural cues, aiming at preserving the spatial perception of the acoustic scene. A well-known binaural noise reduction algorithm is the binaural minimum variance distortionless response beamformer, which can be steered using the relative transfer function (RTF) vector of the desired source, relating the acoustic transfer functions between the desired source and all Microphones to a reference Microphone. In this paper, we propose a computationally efficient method to estimate the RTF vector in a diffuse noise field, requiring an additional Microphone that is spatially separated from the head-mounted Microphones. Assuming that the spatial coherence between the noise components in the head-mounted Microphone Signals and the additional Microphone Signal is zero, we show that an unbiased estimate of the RTF vector can be obtained. Based on real-world recordings, experimental results for several reverberation times show that the proposed RTF estimator outperforms the widely used RTF estimator based on covariance whitening and a simple biased RTF estimator in terms of noise reduction and binaural cue preservation performance.

  • speech enhancement with multichannel wiener filter techniques in multiMicrophone binaural hearing aids
    Journal of the Acoustical Society of America, 2009
    Co-Authors: Tim Van Den Bogaert, Simon Doclo, Jan Wouters, Marc Moonen
    Abstract:

    This paper evaluates speech enhancement in binaural multiMicrophone hearing aids by noise reduction algorithms based on the multichannel Wiener filter (MWF) and the MWF with partial noise estimate (MWF-N). Both algorithms are specifically developed to combine noise reduction with the preservation of binaural cues. Objective and perceptual evaluations were performed with different speech-in-multitalker-babble configurations in two different acoustic environments. The main conclusions are as follows: (a) A bilateral MWF with perfect voice activity detection equals or outperforms a bilateral adaptive directional Microphone in terms of speech enhancement while preserving the binaural cues of the speech component. (b) A significant gain in speech enhancement is found when transmitting one contralateral Microphone Signal to the MWF active at the ipsilateral hearing aid. Adding a second contralateral Microphone showed a significant improvement during the objective evaluations but not in the subset of scenarios t...

  • speech enhancement with multichannel wiener filter techniques in multiMicrophone binaural hearing aids
    Journal of the Acoustical Society of America, 2009
    Co-Authors: Tim Van Den Bogaert, Simon Doclo, Jan Wouters, Marc Moonen
    Abstract:

    This paper evaluates speech enhancement in binaural multiMicrophone hearing aids by noise reduction algorithms based on the multichannel Wiener filter (MWF) and the MWF with partial noise estimate (MWF-N). Both algorithms are specifically developed to combine noise reduction with the preservation of binaural cues. Objective and perceptual evaluations were performed with different speech-in-multitalker-babble configurations in two different acoustic environments. The main conclusions are as follows: (a) A bilateral MWF with perfect voice activity detection equals or outperforms a bilateral adaptive directional Microphone in terms of speech enhancement while preserving the binaural cues of the speech component. (b) A significant gain in speech enhancement is found when transmitting one contralateral Microphone Signal to the MWF active at the ipsilateral hearing aid. Adding a second contralateral Microphone showed a significant improvement during the objective evaluations but not in the subset of scenarios tested during the perceptual evaluations. (c) Adding the partial noise estimate to the MWF, done to improve the spatial awareness of the hearing aid user, reduces the amount of speech enhancement in a limited way. In some conditions the MWF-N even outperformed the MWF possibly due to an improved spatial release from masking.

  • gsvd based optimal filtering for single and multiMicrophone speech enhancement
    IEEE Transactions on Signal Processing, 2002
    Co-Authors: Simon Doclo, Marc Moonen
    Abstract:

    A generalized singular value decomposition (GSVD) based algorithm is proposed for enhancing multiMicrophone speech Signals degraded by additive colored noise. This GSVD-based multiMicrophone algorithm can be considered to be an extension of the single-Microphone Signal subspace algorithms for enhancing noisy speech Signals and amounts to a specific optimal filtering problem when the desired response Signal cannot be observed. The optimal filter can be written as a function of the generalized singular vectors and singular values of a speech and noise data matrix. A number of symmetry properties are derived for the single-Microphone and multiMicrophone optimal filter, which are valid for the white noise case as well as for the colored noise case. In addition, the averaging step of some single-Microphone Signal subspace algorithms is examined, leading to the conclusion that this averaging operation is unnecessary and even suboptimal. For simple situations, where we consider localized sources and no multipath propagation, the GSVD-based optimal filtering technique exhibits the spatial directivity pattern of a beamformer. When comparing the noise reduction performance for realistic situations, simulations show that the GSVD-based optimal filtering technique has a better performance than standard fixed and adaptive beamforming techniques for all reverberation times and that it is more robust to deviations from the nominal situation, as, e.g., encountered in uncalibrated Microphone arrays.