Acoustical characterization of three Ottoman masjids built in Algeria

Abstract

This paper aims at evaluating the acoustical quality of historical Ottoman masjids in Algeria. Measurements were carried out according to current international standards, allowing calculation of acoustical parameters including reverberation time, speech transmission index and Clarity. Three Ottoman masjids located in Algiers (Jedid, Ali-Bitchin, and Safir) were selected. The main purpose of the study was to evaluate the acoustics of the prayer hall in relation to its worship use, assuming as a reference studies of existing masjids. Results showed that two of three worship spaces are generally reverberant under unoccupied conditions (with mid frequency reverberation times of about 3 s), while the other has reverberation time of about 1 s at medium frequencies. Speech intelligibility under unoccupied conditions is between poor and fair for Jedid and Ali-Bitchin masjids, while in Safir masjid values were generally above 0.6. Presence of architectural elements made C50 values quite scattered and characterized by a clear non-symmetrical distribution. Calculations to consider the effect of occupancy were also performed, resulting in significantly drier acoustics with improved clarity.

On the simulation of occupied acoustic conditions of Djedid mosque in Algiers

“…The resulting average of predicted T30 values (Fig. 3a), showed expectedly longer values if compared to those predicted using Sabine's formula in [10]. In fact, in that case, as the characteristics of the carpet were not known, the absorption due to the audience was entirely added to the existing one, also assuming perfectly diffuse sound field (which is not at all obvious considering that the audience is basically distributed on the floor and, partly, on the mezzanine).…”

“…The overall surface area of the added elements was about 1400 m 2 (both sides) for the standing audience and 590 m 2 for the seated one. Thus, based on the absorbing areas given in [13] and an estimated occupancy of 915 persons [10], the relevant absorption coefficients were given in Table 1, with seated audience having higher values because of the reduced surface area. Table 1.…”

“…Acoustic measurements carried out in the mosque were made in compliance with current standards [9] and were described in detail in [10]. Monaural parameters were used in the subsequent analyses.…”

Analysis of the Spatial Distribution Characteristics and Influencing Factors of Traditional Mosque Architecture in the Hehuang Area (China)

“…Research on individual structures mainly focuses on architectural structural performance [21], column styles [22], and visual comfort [23]. Current research is predominantly concentrated in regions with a high Muslim population, such as Saudi Arabia [24], Iran [25], and Algeria [26], in Western Asia and North Africa. From a technical approach, scholars have addressed practical issues in metropolitan development through GIS methods, qualitative and quantitative techniques, as well as demographic and sociological factors.…”