ON THE SIMULATION OF OCCUPIED ACOUSTIC CONDITIONS OF DJEDID MOSQUE IN ALGIERS

Abstract

The old religious buildings are a considerable legacy of ancient knowledge. Their acoustics is part of this heritage, as demonstrated by the ottoman mosques built from the16th to the19th century in Algeria. However, given the many configurations in terms of source placement and worshippers position, one key issue is represented by the difficulty of assessing the acoustics under occupied conditions, which may be evaluated by means of acoustic simulations. Some calculation methods have been proposed in the literature, but they only allow prediction of reverberation time. Conversely, this paper is related to the simulation of the acoustics in the prayer room under occupied situation by means of geometrical acoustic simulations, allowing to obtain the full set of acoustic parameters, if needed. The selected case study is Jedid mosque (Djama'a el Djedid), which was built in Algeria in 1660, in a typical Ottoman style, and later restored in 1855. The mosque was chosen because is large and reverberant to allow a better appreciation of the variations due to occupancy. However, results showed that due to the strong concentration of absorbing elements on the floor, where carpets already contributed to absorb sound, the effect of the occupancy was limited, and acoustic conditions remained poor for speech intelligibility.