In response to the need for research and study of the acoustical problems of urban environments, a mobile laboratory was designed to provide field measurement instrumental capabilities of the quality usually associated only with fixed acoustical laboratories. The facility provides for the field study of the actual acoustical performance of sound-isolating partitions and floor-ceiling assemblies, structureborne sound transmission generated by impacts, vibrating plumbing and electromechanical equipment as installed, and for acquisition of data toward determining relationships between field and laboratory measurement results. Most measurements are conducted from the mobile unit with only loudspeakers and microphones located remotely from the laboratory. For high-rise buildings and situations where lengthy cables are involved, a measurement subsystem is removed and transported readily to the site. Data may be reduced and analyzed at the field site or stored for later reduction and analysis. Some considerations and decisions involved in the preparation of specifications are discussed.

The methods for computing loudness developed by K. E. Zwicker and S. S. Stevens were applied to several complex sounds encountered in our work on architectural acoustics. The loudnesses computed on the basis of Stevens' method did not agree closely with the loudnesses computed by Zwicker's method, and the results obtained by using the two methods were not related to one another in any consistent way. Further, studies with subjects showed that both sets of computations gave results at variance with the responses of the subjects. Investigation of the loudness vs frequency contours for our subjects showed closer conformity to the Fletcher and Munson data than to the more recent equal-loudness contours reported by the National Physical Laboratory, the functions reported by Zwicker, or the band-pressure levels that form the basis for the loudness weighting Stevens' method. However, this feature does not suffice to account for the discrepancies observed.

The methods for computing loudness developed by Zwicker [-Acustica 2, Akust. Beih. 1, 125-133 (1952); Acustica 8, Akust. Beih. 1,237-258 (1958)• and Stevens [J. Acoust. Soc. Am. 28, 807-832 (1956); 11, 1577-1585 (1961)• were applied to several complex sounds encountered in our work on architectural acoustics. The loudnesses computed on the basis of Stevens' method did not agree closely with the loudnesses computed by Zwicker's method, and the results obtained by using the two methods were not related to one another in any consistent way. Further, studies with subjects showed that both sets of computations gave results at variance with the responses of the subjects. Investigation of the loudness-versus-frequency contours for our subjects showed closer conformity to the Fletcher and Munson [J. Acoust. Soc. Am. 5, 82-108 (1933)• data than to the more recent equal-loudness contour reported by the National Physical Laboratory [Brit. Std. 3383, Brit. Stds. Inst. (1961)•, the functions reported by Zwicker, or the band-pressure levels that form the basis for the loudness weighting in Stevens' method. However, this feature does not suffice to account for the discrepancies observed.

The data obtained at the National Bureau of Standards on the sound insulating properties of building structures are summarized. The results of the two previous Supplements to BMS Report 144 (1955) are included, together with later results obtained through January 1964. Single figure ratings, STC and INR, for airborne sound transmission and impact sound transmission, respectively, as well as the octave frequency band spectra of impact noise, are included as additional information. A brief description of the sound-measuring techniques is given.

Land-use planning is often used as a technique for achieving a suitable auditory living environment. Land use alone, however, cannot be the sole noise abatement measure; noise control at the source combined with compatible land-use planning can be most effective. Noise abatement strategies for planning in the environs of airports include operational changes, schedule restrictions, aircraft type restrictions, technological change, airport system change, traffic demand change, encouraging compatible land use, public use, relocation of incompatible use, sensitivity changes, airport environs planning, compensation legal action, regulation and administrative mechanisms, economic incentives, and information. Relative effectiveness and time effectiveness horizons of each are discussed. Alternate means of reducing conflicts between noise sources and surrounding activities are outlined. Implementation of noise abatement strategies and obstacles to implementation are addressed. Ten U.S. airports were studied, including several involved in the Metropolitan Aircraft Noise Abatement Policy Studies (MANAPS) jointly funded by the Department of Transportation and Department of Housing and Urban Development, in order to determine which noise abatement policies and strategies could be most productive.