Determination of the Equivalent Continuous Sound Level (Leq) in Industrial Indoor Space Using GIS-based Noise Mapping

Today, noise is considered to be a damaging factor for human health in various indoor and outdoor environments. In acoustics, noise is defined as the audible energy, which might adversely affect the physical and mental health of living organisms [1]. According to the literature, exposure to excessive noise may lead to hypertension, impaired consciousness, insomnia, stress, tinnitus, and hearing loss [2]. These health effects indicate that noise exposure is currently a major issue in public and occupational environments; as such, noise monitoring is of paramount importance. In this regard, sound level measurement is an inherent element of noise control programs, as well as a pre-requisite to determining the priorities for the identification of areas affected by excessive and efficiency of noise control programs [3]. Since sound energy and sound level could change remarkably depending on time and place, a quantity known as equivalent continuous sound level (Leq) has been fashioned, which is defined as a stable, uniform sound for a given period in a specific location with the same energy level as a non-uniform sound [4]. Leq could be described mathematically, as follows [5]: