title: Acoustical study of a rapid transit system.
mesh_terms: D000162:Acoustics; D001307:Auditory Perception; D001309:Auditory Threshold; D002641:Chicago; D004781:Environmental Exposure; D006801:Humans; D007883:Legislation, Medical; D008433:Mathematics; D008452:Maximum Allowable Concentration; D009622:Noise; D009787:Occupational Medicine; D011890:Railroads; D013016:Sound; D013223:Statistics as Topic; D014505:Urban Population