A Study of a various Acoustic Beamforming Techniques Using a Microphone Array (original) (raw)

Dual Microphone Beamforming Algorithm for Acoustic Signals

International Journal of Computer Applications, 2015

This paper covers delay-and-sum beamformer and Filter and sum beamformer-Minimum Variance Distortion-less Response (MVDR) beamformer. Both the beamformers were simulated and tested in terms of noise source separation at various frequencies and computational complexity using MATLAB. Even though Generalized Side-Lobe Cancellers (GSC), Superdirectivity and Post-Filtering are also available. It actually covers two-sensor array beamforming which can be extended to multisensory array. MVDR beamformer gave better results as compared to delay-and-sum beamformer, as it adopts to noise condition and also improves the beamformer output, but has a higher computational complexity. Seeing the simulation results, MVDR proves to be a better option for implementing on smart phone applications.

Analysis of Beamforming Methods for Speech Enhancement

Nowadays, hands-free technology has been rapidly increasing in communication systems. It allows a natural form of communication, as if the communication partner was right next to you, the major problem in these systems is the addition of background noise. In this paper implemented beamforming methods for noise reduction in hands-free communication. A beamformer is an array of microphones, which can do spatial filtering. Speech data has been collected using linear microphone array and processed using delay-and-sum beamformer (DSB) and generalized side-lobe canceller (GSC) algorithms. The performance of these techniques analyzed using objective and subjective methods. It has been observed that the beamforming techniques are useful for hands-free communication.

Sound Source Localization with DAS Beamforming Method Using Small Number of Microphones

Localization of the sound source using microphone arrays is largely done by Acoustical Holography or Beamforming method. In this paper we present an implementation of Delay-And-Sum algorithm for beamforming computation using various microphone arrays. A MATLAB code was implemented for postprocessing of obtained acoustic signals. There is also included a description of the fractional delay filter implementation to delay the signal samples by racional values of sample period. The goal of this paper was comparing the accuracy of the source localization with the microphone arrays using small number of microphones. The results of the localization of several noise sources by the different types of arrays is presented.

Speech Enhancement Using Microphone Arrays

This module is designed to give the students a practical understanding of performing speech enhancement using microphone arrays and demonstrate the difference between different techniques. This module is closely related to the lecture Speech Enhancement given by Prof. Dr. ir. Emanuël Habets. In this exercise, the students will implement a commonly used spatial signal processing technique known as beamforming, and analyse the performance of two different beamformers, a fixed beamformer known as delay-and-sum beamformer and a signal-dependent beamformer known as minimum variance distortionless response (MVDR) beamformer, for a noise and interference reduction task. Their performances will be compared via objective measures to demonstrate the advantages of the signal-dependent beamformers.

An Implementation of Beamforming Algorithm on FPGA Platform with Digital Microphone Array

AES, 2015

The goal of the project described in this paper was to design an acoustic system for localization of the dominant noise source by implementation of the conventional delay-and-sum beamforming algorithm on FPGA platform with a sound receiver system based on digital MEMS microphone array. The system consists of a platform for acoustic signal acquisition and data processing (microphone array, interface and central block), and a platform for monitoring and control (a computer with a user application). Such configuration provides the execution of the beamforming algorithm in real time. Additionally, FPGAs are bringing many benefits in terms of safety, reliability, rapidity, and power consumption. The platform was tested and verified with various microphone array configurations and results are presented in the paper.

Design of microphone phased arrays for acoustic beamforming

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2018

The design of a microphone array affects the performance of beamforming algorithms in the localization and evaluation of acoustic noise sources. This paper addresses a circular phased array design for near-field aeroacoustic measurements in a closed-test-section wind tunnel. Microphones were distributed in rings and occupied an equal aperture area-each ring could have a different number of microphones. The array performance was evaluated through the dynamic range and array resolution given by the beamwidth. The array designed for the exploration of the novel approach had 112 microphones and 950-mm aperture. In comparison with classical designs, also optimized for the same number of microphones and aperture, the approach provided the best array resolution and a high dynamic range level almost uniform over the frequency range of interest (800 to 20,000 Hz). Microphone shading was also assessed for improving the array performance, and the employment of only the outermost microphones (the innermost ones were shaded) reduced approximately 40% the array beamwidth.

Adaptive Beamforming with a Microphone Array

—A robust and optimized system architecture has been developed and designed for adaptive beamformer with a Microphone Array. The system includes following subsystems-MMSE STSA Estimator, DOI (Direction of Interest) Estimator and an Adaptive Beamformer. The system architecture has been implemented and tested for Xtensa Processor which was configured for HiFi-2 DSP Standard for audio processing.

Moving microphone arrays to reduce spatial aliasing in the beamforming technique: Theoretical background and numerical investigation

The Journal of the Acoustical Society of America, 2008

This paper introduces a measurement technique aimed at reducing or possibly eliminating the spatial aliasing problem in the beamforming technique. Beamforming main disadvantages are a poor spatial resolution, at low frequency, and the spatial aliasing problem, at higher frequency, leading to the identification of false sources. The idea is to move the microphone array during the measurement operation. In this paper, the proposed approach is theoretically and numerically investigated by means of simple sound propagation models, proving its efficiency in reducing the spatial aliasing. A number of different array configurations are numerically investigated together with the most important parameters governing this measurement technique. A set of numerical results concerning the case of a planar rotating array is shown, together with a first experimental validation of the method.

An Acoustic MIMO Framework for Analyzing Microphone-Array Beamforming

2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07, 2007

Although a signi cant amount of research attention has been devoted to microphone-array beamforming, the performance of all the developed algorithms in practical acoustic environments is still far from meeting our expectation. So further research efforts on this topic are indispensable. In this paper, we treat a microphone array as a multiple-input multiple-output (MIMO) system and develop a general framework for analyzing performance of beamforming algorithms based on the acoustic MIMO channel impulse responses. Under this framework, we study the bounds for the length of beamforming lter, which in turn shows the performance bounds of beamforming in terms of speech dereverberation and interference suppression. We also discuss the intrinsic relationships among different classical beamforming techniques and explain, from the channel condition point of view, what the prerequisites have to be ful lled in order for those techniques to work.