Perlpnnon Computers ind. Engng Vol. 35, Nos 1-2, pp. 327-330, 1998 O 1998 ElsevierScienceLtd. All rightsreserved Printed in GreatBritain PII: S0360-8352(9g)00086-2 0360-8352/98 $19.00 + 0.00 NOISE REDUCTION USING NONLINEAR OPTIMIZATION MODELING Sherif M. Waly and Bhaba IL Sarker Department of Industrial and ManufacturingSystems Engineering Louisiana State University Baton Rouge, LA 70803 ABSTRACT The primary objective of this study is to develop a 3D model to determine the maximum allowable noise exposure time. This model allows the presence of multiple uncorrelated sources. The model provides an optimal arrangement for locating various machinery and equipment in the plant layout and also takes into consideration the acoustic characteristics of materials used in constructing the room. A detailed description of the models and results obtained will be presented and discussed. © 1998 Elsevier Science Ltd. All rights reserved. KEYWORDS Noise, acoustic design, noise control, layout, and nonlinear optimization. INTRODUCTION In its broadest sense, noise is simply defined as unwanted sound. Controlling workplace noise has been of great concern to the general public as well as governmental agencies. Several methods and approaches concerning noise control have been documented in the literature. Basically, a noise control program can be classified into two categories, engineering and administrative controls. The Occupational Safety and Health Administration (OSHA) requires that engineering controls be applied to solve the noise problem and bring the sound levels into conformance with the required levels. This includes reducing machinery noise through redesign, replacement with quieter equipment, and reducing the transmission of noise along the path from source to receiver. Administrative controls such as work rotation, and work/rest schedule can limit the time an employee is exposed to given noise levels. Noise can prevent people from performing at their maximum ability and efficiency, it can deprive them of enjoying their leisure to the fullest extent, it can interfere with their sleep, it can result in increased nervous tension with associated psychological effects, and most particularly it can result in damage to the audio-sensory mechanism and lead to premature and permanent loss of hearing. Controlling workplace noise in industries has received an acceptance both from general mass and the government. Much attention and awareness is directed toward the effects of noise on he environment and health, which necessitate extensive research on sound and the laws that govern it. OSHA was organized by the U.S. Department of Labor and was given authority to set up and enforce regulations aimed at providing greater safety to people who are normally exposed to somewhat hazardous working conditions and environments, including noise exposures. Several methods and approaches concerning noise control have been documented in the literature. Basically, a noise control program can be classified into two categories, engineering and administrative 327