Acoustic Propertees of Large Spaces at Level L2 and L3 at new Zagreb Airport Passenger Terminal

In Zagreb (Republic of Croatia) there is ongoing the construction of a new International Zagreb Airport (MZLZ – Međunarodna zračna luka Zagreb) passenger terminal. As a part of the terminal especially demanding is arrival and departure terminal hall due to the large volume requirements and international standards that determine the maximum allowed reverberation time for such kind of spaces. Because of the importance of voice alert and emergency information to the passengers, special attention is given to the speech intelligibility. On the other hand, in the international standard (EN 54 Fire detection and fire alarm systems) minimum sound pressure level and speech intelligibility of sound reproduced through public address system is strictly defined for emergency cases. According to this, the analysis of acoustic properties of the large spaces at levels L2 and L3 with acoustic treatment proposed with initial project has been done. Since the results did not meet the minimum required conditions, a new solution is proposed. With this new solution the best possible results with minimum investments are achieved. The proposal for the further improvement of acoustic properties of those spaces in order to improve the acoustic conditions, primarily related to the problem of intelligibility is also provided.