A study of the accuracy of mobile technology for measuring urban noise pollution in large scale participatory sensing campaigns

International audienceThe study reports on the relevancy and accuracy of using mobile phones in participatory noise pollutionmonitoring studies in an urban context. During one year, 60 participants used the same smartphonemodel to measure environmental noise at 28 different locations in Paris. All measurements were performedwith the same calibrated application. The sound pressure level was recorded from the microphoneevery second during a 10-min period. The participants frequently measured the evolution of thesound level near two standard monitoring sound stations (in a square and near a boulevard), whichenables the assessment of the accuracy and relevancy of collected acoustic measurements. The instantaneousA-weighting sound level, energy indicators such as LA,eq, LA10, LA50 or LA90 and event indicators suchas the number of noise events exceeding a certain threshold La (NNELPLa) were measured and comparedwith reference measurements. The results show that instantaneous sound levels measured withmobile phones correlate very well (r > 0.9, p < 0.05) with sound levels measured with a class 1 referencesound level meter with a root mean square error smaller than 3 dB(A). About 10% of the measurementsfor the boulevard location (respectively 20% for the square) were inaccurate (r < 0.3, p < 0.05).Nevertheless, mobile phone measurements are in agreement for the LA50 and the LA90 acoustic indicatorswith the fixed station (4-m high) measurements, with a median deviation smaller than 1.5 dB(A) for theboulevard (respectively 3 dB(A) for the square)