The value gotten for the medium one was of 104,7 dB (), indicating that 50% of the values of the levels of measured noises are above of this value, about 35,0 dB () more than the level criterion established in 40,0 NBR 10151 and about dB () more than the level of criterion established in NBR 10152. In relation to the values of the quartiles, it was observed that 50% of the emitted values of noise in the activities, that is half of the measured values, is around 95,0 105,0 dB () e, in relation to the percentiles, was verified that, for 70,0 dB (), the percentile biggest is P11, indicating that 89% of the noise levels are above of the level criterion of NBR 10151. Now, comparing the value of 65,0 dB () the biggest percentile is the P1, indicating that 100% of the values they are above of the value established for the NBR 10152/NR 17. Being overcome the data of all the measurements and becoming fullfilled a frequency distribution, were verified that this is come close to a normal distribution, as if can see in Figure 02. Figure 02 Histograma of the distribution of all the data of the measurements Knows that not yet a norm exists that establishes values for acoustic comfort in the work environments that they do not demand intellectual request. What it exists is the NR-15 that establishes values for sound pressure levels that they can cause PAIR in labor environments in function of the exposition time. Table 04 presents the values of Leq () gotten in five (5) measurements of noise for PAIR, beyond the time of each measurement, the criterion of the NR-015 and the Dose equivalent for eight (8) working hours. Table 04 Comparison enters the values of Leq () measured and prescribed by the NR-15 Activity Time of Measurement (hours) Leq () NR-15 dB () Dose for 8 hours % Welding 11:22 91,2 85,0 238,2 Welding 11:30 95,5 85,0 433,0 Jateamento 08:07 87,3 85,0 140,0 Welding 08:05 86,5 85,0 135,0 Jateamento 08:33 87,7 85,0 145,7 Analyzing Figure 03, that it is the graphical representation of Table 04, for a comparison with the values of the NR-15, can be verified that, for all the measurements, the value of Leq (), is always above of the level criterion established for the NR-15, especially for measurement 2 (activity of welding) where the value is about 10,0 dB () above of the boundary-value of the NR-15, form that if it will not have use of auditory protector on the part of the employees that these activities act in all, certainly will occur auditory loss in the same ones in elapsing of the time.