insitu - acústica, initiated its activity in 2000 with the accomplishment of assays in surrounding acoustics passing since the year of 2003 to also execute assays of acoustics of buildings. The laboratory insitu is recognized by the IPAC norm NP EN ISO/IEC 17025 - requisite of ability for laboratories of acoustics and vibrations.
	the decibel dB, is the unit of measure of the attenuation, amplification, power or sonorous pressure; to adjust dB to the sensitivity of the human ear, it's used a scale with decimal logarithmic variation; in this scale the inferior threshold of hearing corresponds the 0 dB and in the superior threshold the 120 dB.