Some characteristics of noise in air-conditioned landscaped offices

In the present study, noise measurements were carried out in 26 air-conditioned landscaped offices during lunch and office hours. The noise spectra show that, in general, the noise from office activities is of a frequency higher than 500 Hz. A-, B- and C-weighted sound levels are also calculated and it is found that linear relationships exist between these weighted levels. In addition, simple formulae are proposed for the estimations of noise criterion (NC) and noise rating (NR) from the A-weighted sound level which is also known as the equivalent sound pressure level. The air-conditioning systems affect the noise levels, NC and NR, but not the basic relationships between weighted sound levels, NC and NR.