The active attenuation of the airborne noise generated from a high-speed CD-ROM system is investigated using model-based feedback control methods. A mathematical model of the physical system is developed based on a onedimensional acoustic duct system. The critical system parameter, acoustic terminal impedance, is estimated using the eigenstructure tests through the system identification method....

The presence of strong acoustic feedback degrades the convergence speed of the active noise control (ANC) filter, and in the worst case the ANC system may become unstable. Here we present an overview of the existing methods developed to neutralize the effects of acoustic feedback. We identify the problems with the existing methods, and propose a new method. The proposed method uses three adapti...

BACKGROUND Making high-quality health care available to all women during pregnancy is a critical strategy for improving perinatal outcomes for mothers and babies everywhere. Research from high-income countries suggests that antenatal care delivered in a group may be an effective way to improve the provision, experiences, and outcomes of care for pregnant women and newborns. A number of research...

This paper presents the design and implementation of adaptive feedback active noise control system (ANC) for head phone applications. Active Noise Control is a technique of acoustic noise reduction using a secondary source of sound which produces ”antinoise” to cancel the primary noise. In this paper, narrow band single channel feedback ANC for headsets application is focused upon. The filter w...

This paper presents the development and DSP implementation of a stable ANC feedback system with online secondary path modelling, using the Normalized Filtered-X Least Mean Square with Noise Addition algorithm (NFXLMS-NA), for acoustic noise cancellation. In this paper, the feedforward and the feedback ANC systems are described briefly; the basic of the FXLMS algorithm and its structure is discu...

A popular approach for Active Noise Control (ANC) problems has been the use of the adaptive Filtered-X Least Mean Squares (FXLMS) algorithm. A fundamental problem with feedforward design is that it requires both reference and error sensors. In order to reduce the size, cost and physical complexity of the control system a feedback controller can be utilized. In contrast with FXLMS a feedback con...

Background & aim: Active participation of men in antenatal care and their considerable knowledge about this issue is resulted in favorable pregnancy outcomes. This study aimed to assess the knowledge and practices of male partners regarding antenatal care (ANC) and their associated factors in district Swat, Khyber Pakhtunkhwa, Pakistan (KPK). Methods<...

This paper investigates the stability problem of the feedback active noise control (ANC) system, which can be caused by the modeling error of the electro-acoustic path estimation in its feedback mechanism. A stability analysis method is proposed to obtain the stability bound as a form of a closed-form equation in terms of the delay error length of the secondary path, the ANC filter length, and ...

In a response to a growing demand for environments of 70dB or less noise levels, many industrial sectors have focused with some form of noise control system. Active noise control (ANC) has proven to be the most effective technology. This paper mainly investigates application of neural network on self-adaptation system in active noise control (ANC). An active silencing control system is made whi...