A Hybrid Approach to Noise-Reduced Pods in Urban Areas

Urban environments generate intense and incessant noise, creating unnecessary distractions and contributing to various health issues such as hearing loss and stress. To address the concerns created by short-term exposure to acute noise pollution, this project proposes a noise-reduced pod, which integrates passive and active noise cancellation technology to effectively reduce high and low frequency signals, respectively. For the passive approach, the pod was modeled with highly noise absorbent and reflective materials to most effectively attenuate sound waves. For the active approach, electronic components were utilized to collect and output signals, and a Filtered-x Least Mean Square (LMS) Finite Impulse Response (FIR) adaptive filter was created to process the input noise and produce the anti-noise. It was determined that polyurethane foam and double-glazed plexiglass are the best materials for sound absorption, rounded edges are the best structure for sound reflection, and an LMS step size of 0.008 provides the best adaptive filtering. The technology, which achieved a significant noise reduction, was incorporated in a novel pod design for use in smart cities.