Modeling with CadnaA to estimate the probability of awakening associated with train horns

摘要

The Rutgers University Noise Technical Assistance Center conducted a longtermrnacoustical study to assess the noise exposure of residents in Teaneck, NJ to noisernassociated with idling freight trains. One of the noise sources evaluated was idle-relatedrnhorn usage, at locations other than grade crossings. Trains on an adjacent track passing anrnidling locomotive regularly blow their horn as they approach and pass an idling train. Thernprimary impact on the community due to this type of horn use is sleep disturbance. Inrnorder to evaluate this impact, an analysis was performed using CadnaA acousticalrnmodeling software in an innovative manner, to evaluate the probability of awakeningrn(POA) as a result of idle-related horn usage based upon ANSI/ASA S12.9-2008/Part 6, arnstandard for estimating awakenings. The standard presents a series of formulae thatrncalculate the POA as a function of A-weighted sound exposure level (ASEL) of a single orrnseries of noise events. Other factors influencing the POA are time since retiring andrnwhether the sound is new or existing. The model output is a graphic of equal-probabilityrncontours showing the POA at least once throughout the night.