Signal Processing Approach for the Characterization and Modeling of Urban Noise: A Case Study of a City in Western Côte d'Ivoire
T. Guié Toa Bi *
UFR Sciences and Technologies, University of Man, Man, Côte d'Ivoire.
Bernard N’Zebaud
UFR Sciences and Technologies, University of Man, Man, Côte d'Ivoire.
Sandjé Marcelin
Digital Research and Expertise Unit (UREN), Virtual University of Côte d'Ivoire (UVCI), Abidjan, Côte d'Ivoire.
Sié Ouattara
Houphouët Boigny National Polytechnic Institute (INPHB), Yamoussoukro, Côte d'Ivoire.
Alain Clement
LARIS, SFR MATHSTIC, University of Angers, Angers, France.
*Author to whom correspondence should be addressed.
Abstract
Urban environmental noise is insufficiently characterized in many secondary cities in sub-Saharan Africa. This exploratory study characterizes short-duration urban sound recordings from five neighborhoods of Duékoué, Côte d’Ivoire (Kokoman, Antenne, Résidence, Belleville, and Guitrozon). Recordings were obtained with a Samsung Galaxy A13 smartphone at 09:00, 12:00, and 17:00 on Monday, Thursday, and Sunday and processed in MATLAB to derive A-weighted equivalent levels (LAeq), percentile levels (L10, L50, and L90), nuisance indices (LNP and TNI), loudness-related descriptors, spectral centroid, zero-crossing rate, and energy fractions in broad frequency bands. The processing chain emulated standard sound-level calculations; however, because the smartphone system was not traceably calibrated against a reference sound level meter and was not demonstrated to conform to IEC 61672, the reported sound-pressure levels are interpreted as approximate estimates rather than certified regulatory measurements. Across the tabulated sites, estimated LAeq ranged from 62.62 dB(A) in Antenne at 17:00 to 72.69 dB(A) in Résidence at 17:00. Temporal profiles differed among neighborhoods, while mid-frequency energy generally represented the largest share of the spectrum. The findings show that smartphone-based signal processing can provide useful comparative information on urban acoustic patterns when its metrological limitations are stated explicitly. Longer, traceably calibrated monitoring is required before formal compliance or population-exposure conclusions can be drawn.
Keywords: Environmental noise, urban acoustics, signal processing, Duékoué, LAeq, spectral analysis, smartphone measurement