Adaptive Active Noise Cancelling System for Headphones on Raspberry Pi Platform

Author(s):  
Piotr Sykulski ◽  
Konrad Jedrzejewski
Author(s):  
Edgar Lopez-Gaudana ◽  
Pablo Betancourt ◽  
Enrique Cruz ◽  
Mariko Nakano-Miyatake ◽  
Hector Perez-Meana

Circuit World ◽  
2020 ◽  
Vol 47 (1) ◽  
pp. 1-10
Author(s):  
Ali Ghasemi ◽  
Farzin Shama ◽  
Gholamreza Karimi ◽  
Farshad Khosravi

Purpose The purpose of this paper is to provide appropriate methods for reducing the abnormalities on the extracted fetal heart signal from the maternal electrocardiogram (ECG). Design/methodology/approach In this regard, the extracted signal of the fetal heart from the mother, improved using an active noise cancelation (ANC) system. It uses commonly adaptive algorithms of normalized least mean squares (NLMS). In the present paper, fetal extraction and denoising methodology are proposed. This methodology uses a combination of the NLMS algorithm with Savitzky–Golay (S-G) filter. Findings The obtained results show that a combination of NLMS algorithm with filter coefficient of 15 and µ = 0.02 and S-G filter has a better qSNR (qSNR = 3.6727) and good performance for fetal ECG extraction in comparison with the other works for average fmSNR in the range of −30 to −15 dB. Also, with considering the SNR value of −24.7 dB before filtering and SNR = 3.1861 dB after filtering; the SNR improvement of 27.8861 dB has been obtained. Originality/value A new method in the extract and noise reduction of fetal ECG from maternal ECG by the combination of NLMS algorithm and S-G filter is proposed.


2020 ◽  
Vol 165 ◽  
pp. 107335
Author(s):  
Feng Niu ◽  
Xiaojun Qiu ◽  
Dong Zhang

2013 ◽  
Vol 99 (5) ◽  
pp. 822-827 ◽  
Author(s):  
Brett R. C. Molesworth ◽  
Marion Burgess ◽  
Amy Chung

2016 ◽  
Vol 861 ◽  
pp. 537-544 ◽  
Author(s):  
Christian Tauber ◽  
Egzon Bajraktari ◽  
Josef Lechleitner ◽  
Ulrich Pont ◽  
Ardeshir Mahdavi

Within an ongoing project, we explore the potential of double skin facades to provide both noise control and natural ventilation capability. Three strategies are investigated: i) Manipulation of sound paths via offset of the openings in the two shells of the façade; ii) Application of absorbing materials in the interstitial space of the façade; iii) Active noise cancelling methods utilizing wave-destructive interference. This contribution describes the overall project but focuses primarily on the active noise cancellation approach. Aside from a comprehensive background research on existing technology, we undertook the design of an actual setting for noise cancellation testing with suitable low-cost components as a proof-of-concept. Results of the experiments are expected to inform subsequent efforts to include noise-cancelling technology in double skin facades.


Sign in / Sign up

Export Citation Format

Share Document