In swine production, it is known that environmental factors have a great influence on animal behavior. An innovative method to quantify and classify uncomfortable situations for the animals is with automatic registration of noise levels emitted by these animals in intensive production systems. Thus, the objective of this work was to assess the influence of environment variables (temperature and air humidity) in the emission of noise levels by piglets in an intensive production system. The experiment was carried on a commercial swine farm during the period from April to June of 2008. The data collected include sound pressure levels (noise) emitted by piglets in nursering phase, and environmental variables (temperature and air relative humidity) inside the facility. Decibelimeters were used to record noise levels and HOBOS data loggers were used to measure and record environmental variables. Enthalpy and THI comfort indexes were used to characterize the thermal environment. Analysis of correlation and simple regression were used. Piglet's noise levels (NL piglets) showed a correlation to the environmental variables, air temperature and air humidity, so, it was possible, through a regression analysis, to estimate NLpiglets related to the environmental variables to the studied environment.