Legislation exists in most countries to assess noise annoyance by the measurement and analysis of the single global value of dBA. This parameter, however, is inadequate for determining actual annoyance in people, due to the non-auditory effect of hearing low frequency and infrasound in dwellings and workplaces. Some countries propose advanced methods of determining this annoyance, while others propose to use ISO standards; both cases require highly trained acoustics professionals to apply them. Another problem in assessing noise irritation is determining where (in what position) the SLM should be placed within a home or office, since this affects the score of the noise level as a result of the presence of noise modes and resonance. Therefore, it is recommended that measurements be taken in more than one microphone position. The ever-lowering costs of technology and the diffusion of SLM analyzers have been a benefit, as most acoustic instruments now have powerful processing ability. This Paper presents the results of measurements made in enclosures (such as housing and hotel rooms, as well as in offices and workplaces), where it is shown that if the noise level is evaluated in dBG instead of dBA, the position of the microphone inside the enclosure is irrelevant since the sound field in low frequency and infrasound is more diffuse and resonance modes do not affect the ECSPL record very much. It would be necessary only if low frequency and infrasound needed to be analyzed.
