Keep the Noise Down!
OPV-based energy harvesting sensors for urban noise pollution
In the past 24 months ~200,000 noise complaints have been logged by the 311 city service hotline for New York City (Source: NYC Open Data). This is an average of around 274 calls a day, and means that roughly 1 in 84 New York City residents will lodge a noise complaint with the city in any given year.
Studies in urban noise pollution over the past 40 years have established correlations between urban noise and well-being, education and mental health. Several studies have linked noise to childhood development¹; subsequent research² has correlated chronic noise exposure with a variety of health issues, including cardiovascular stress in children. As a result, a variety of public policy initiatives have been taken in cities in the United States and Japan. More recent studies have leveraged advances in telecommunications and computer technology to measure urban noise more effectively. In 2009, Sony measured personal exposure to noise using smartphones, enabling the development of crowd-sourced noise maps of urban areas³. A similar project was undertaken by Motivity in the Tenderloin neighbourhood of San Francisco in 2010 using stationary decibel meters at key intersections⁴.
London’s strategic noise policy was defined in March 2004 and more recently New York Mayor Michael Bloomberg announced a policy to control urban noise pollution. DEFRA’s Noise Mapping England project, which demonstrates how noise mapping can be built from computer modelling, using inputs such as traffic flow data, road/rail type and geographic features such as buildings and the shape of the ground, was instigated as a result of European directives in this area.
Most of these studies are concerned with ambient noise (e.g. background noise such as traffic). These are clearly useful since they enable noise maps to be produced as part of transport strategies, assessing alternative transport options (fuel cell buses) and different highways strategies (removing road humps) etc. However, there are other noise agents which are currently not mapped: noise from neighbours, shops/bars, road- and building-works, commercial dwellings etc. At present there is no mechanism for recording street-level or building noise in real-time, nor has there been work on associating noise maps with correlative data such as police complaints, crime records and medical reports etc.
According to Columbia Mailman School of Public Health researcher Robyn Gershon, 20 million adults and 10 million children in the United States suffer from “noise-induced hearing loss.”
The Occupational Safety and Health Administration is responsible for workplace noise in the US. The agency stated in 2012 that it would take 138 years to inspect every workplace in the US. At the University of Warwick we are building new technology for the real-time street and building monitoring of urban noise. Using third-generation organic photovoltaic (OPV)-based autonomous wireless sensors and employing environmentally friendly components, including silicon-based battery alternatives, we are developing and deploying energy harvesting noise sensors as part of CUSP New York’s Living Laboratory.
The sensors used in this project are an innovative technology developed through a partnership between Molecular Solar Ltd (a Warwick spin-out company established to commercialise third-generation solar cell technology) and the University of Warwick’s Engineering and Computer Science Departments (whose expertise includes novel microsensor technology and distributed wireless sensor network design). The sensors can equally sense humidity, temperature, light, gases (CO, NO₂, CO₂, H₂, CH₂), VOCs (alcohols, ketones, aldehydes, toluene etc.) and explosives. The application space is therefore diverse, and spans environment, government, healthcare, national security and military applications.
¹ Bronzaft and McCarthy, 1975; Bronzaft, 1981
² Evans, Hygge, and Bullinger, 1995
³ Maisonneuve et al, 2009
⁴ TenderNoise, 2011