The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, the problem of estimating the directions of arrival (DOAs) for an unknown number of sound sources is addressed using a microphone array. In outdoor environments, the reverberation is not considered, so the pure delay mixture model is typically adopted here. Since the sound signal is usually wide-band and non-stationary, the Short Time Fourier Transform (STFT) is employed. However in...
The acoustic recognition module of the unattended ground sensor (UGS) system applied in wild environments is faced with the challenge of complicated noise interference. In this paper, a small-aperture microphone array (MA)-based acoustic target classification system, including the system hardware architecture and classification algorithm scheme, is designed as a node-level sensor for the application...
This paper presents a system consisting of an array of thin-film microphone channels on glass, which can be formed on large substrates. Each microphone channel consists of a polyvinylidene difluoride (PVDF) piezoelectric transducer as well as amplifier and scan circuits basedon amorphous-silicon (a-Si) thin-film transistors (TFTs). The scan circuits multiplex signals from multiple channels to a CMOS...
This paper presents a system consisting of an array of thin-film microphone channels on glass, which can be formed on large substrates. Each microphone channel consists of a polyvinylidene difluoride (PVDF) piezoelectric transducer as well as amplifier and scan circuits based on amorphous-silicon (a-Si) thin-film transistors (TFTs). The scan circuits multiplex signals from multiple channels to a CMOS...
This paper addresses the problem of enhancing a speech signal acquired by a microphone array used for hands-free voice communication applications. A new algorithm based on the coherence function developed in the wavelet domain and applied to the beamforming output signal is presented. The wavelet coherence function based nonlinear post-filtering provides a further noise suppression. Its performances...
this paper proposes a directional noise suppressor with a specified constant beamwidth. A directional gain is calculated based on interchannel phase difference and combined with a spectral gain commonly used in single-channelnoise suppressors (NSs). The beamwidth can be specified as passband edges of the directional gain. In order to implement frequency-independent constant beamwidth, frequency-proportionate...
In this work, we investigate the efficacy of Micro Electro-Mechanical System (MEMS) microphones, a newly developed technology of very compact sensors, for multichannel speech enhancement. Experiments are conducted on real speech data collected using a MEMS microphone array. First, the effectiveness of the array geometry for noise suppression is explored, using a new corpus containing speech recorded...
Source localization has been studied in the spatial domain using differential geometry in earlier work. However, parameters of the sensor array manifold have hitherto not been investigated for source localization in spherical harmonics domain. The objective of this work is to represent and model the manifold surface using differential geometry. The system model for source localization over a spherical...
We investigated the basic principle of how spatial signals should be captured with a microphone array to estimate each source signal and its practical implementation. Most conventional studies on array signal processing have been focused on the design of beamforming and Wiener filters. To achieve further effective noise reduction, designing an optimum array structure to segregate a target from other...
The ability of robots to listen to several things at once with their own “ears”, that is, robot audition, is an important factor in improving interaction and symbiosis between humans and robots. The critical issue in robot audition is real-time processing and robustness against noisy environments with high flexibility to support various kinds of robots and hardware configurations. This paper first...
This work focuses on an adaptive beamformer in a hearing aid application using a generalized sidelobe canceller structure (GSC). In this application, the constraint and blocking matrices in the GSC structure are specifically designed using an estimate of the transfer functions between the target source and the microphones to ensure optimal beamformer performance. We show that, in practice, the GSC...
In this paper we propose a novel multi-channel algorithm to separate simultaneous speakers in an environment where the microphone array is subject to movement. When the microphones are mounted to a person's head, for instance, the movements can lead to ambiguities with respect to the sources and to distortions in the processed signal. The proposed system estimates the direction-of-arrival of the speaker's...
We propose a novel algorithm to design an optimum array geometry for source localization inside an enclosure. We assume a square-law decay propagation model for the sound acquisition so that the additive noise on the measured source-microphone distances is proportional to the distances regardless of the noise distribution. We formulate the source localization as an instance of the “Generalized Trust...
This paper describes an improved complementary beam-forming microphone array with a new noise adaptation algorithm for efficient speech enhancement. Complementary beamforming is based on two types of beam-formers designed to obtain complementary directivity patterns each other. In this system, two directivity patterns of the beamformers are adapted to the noise directions so that the expectation values...
Recorded speech signal separation from noise and interference using multichannel microphone array is a prominent area of research in audio engineering. Beamforming technique calculates time delay among the array signals and projects a beam for maximum output power in the space. This paper presents two basic beamforming techniques to suppress the noise and interference from the recorded speech in noise...
In this paper, a multi-channel active noise control (ANC) using parametric array loudspeakers (PALs) is proposed to solve the noise problem in a factory. The PAL is a type of directional loudspeaker making use of the nonlinear acoustic effects. There are two advantages when PALs are used as the secondary sources in a multi-channel ANC system. First, noise levels can be reduced at the targeted locations,...
Target of this research is that patient can listen to sounds of own internal organs, be interesting in and have active involvement in own medical treatment. However, there is nothing in the world patient can listen to the sound of own internal organs. Any patient will be not able to make out sound of particular organ, using stethoscope. Doctor uses the stethoscope for diagnosis catching weak sound...
This paper addresses sound source detection in an outdoor environment using a quadrotor with a microphone array. Since the previously reported method has a high computational cost, we proposed a sound source detection algorithm called MUltiple SIgnal Classification based on incremental Generalized Singular Value Decomposition (iGSVD-MUSIC), which detects sound source location and temporal activity...
In this paper, an unsupervised adaptation algorithm for the microphone array topology of a humanoid robot is proposed, so that the spatial filtering performance is improved. In the given exemplary case, the target suppression (‘blocking’) performance of a geometrically-constrained BSS (GC-BSS) algorithm is shown to improve by the adaptation of the array topology. As a decisive feature, an online performance...
A microphone array post-filter design effective in various noise environments is proposed for implementation in a hands-free speech interface. Although various post-filter designs have been studied, few methods have been effective in practical use since different types of sound sources, such as spatially coherent target/interference sources and incoherent background noise, are included in the observation...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.