A master thesis from Aalborg University
Adaptive Noise Cancellation For Electronic Stethoscopes
[Adaptiv støjreduktion til elektroniske stetoskoper]
Author(s)
Term
4. semester
Education
Publication year
2025
Submitted on
2025-05-28
Pages
150 pages
Abstract
This thesis investigates adaptive noise cancellation for improving heart and lung sound recordings in noisy environments, with a focus on resource-limited settings like rural India. Environmental and equipment noise often degrade auscultation quality, affecting diagnosis. To address this, adaptive filters (LMS, NLMS, RLS) and Independent Component Analysis (FastICA) were evaluated. All methods met the target of improving SNR by at least 20 dB in synthetically mixed signals, confirming their theoretical effectiveness. RLS stood out among the filters, achieving up to 34 dB improvement and performing reliably across noise types using fixed hyperparameter. While FastICA showed strong results in controlled conditions, it was unreliable in real-world recordings due to timing and environmental sensitivity. In contrast, RLS with fixed hyperparameter proved practical and robust for real-life use. These results highlight RLS-based adaptive filtering as a simple, effective solution for enhancing auscultation in noisy conditions, supporting broader deployment in frontline health settings.
Documents
Colophon: This page is part of the AAU Student Projects portal, which is run by Aalborg University. Here, you can find and download publicly available bachelor's theses and master's projects from across the university dating from 2008 onwards. Student projects from before 2008 are available in printed form at Aalborg University Library.
If you have any questions about AAU Student Projects or the research registration, dissemination and analysis at Aalborg University, please feel free to contact the VBN team. You can also find more information in the AAU Student Projects FAQs.