When measuring the reverberation time in a room, it is well known that the result, especially at high frequencies, depends on the temperature and relative humidity (RH) of the air. Room acoustic measurements were made with the integrated impulse response method in a swimming hall under different atmospheric conditions, ranging from 31,2 °C and 88,1 % RH to 27,7 2 °C and 35,5 % RH.

The air absorption can be quite high in case of very dry air. A method to normalise acoustic measurement results to a standard atmosphere (20 °C and 50 % RH) has been suggested [1]. Although the measurements in the current case were made under quite extreme conditions, the influence of the air absorption turned out to be quite limited due to high humidity. Only the results at the 8 kHz octave show a significant variation with the atmospheric conditions.