Reflectors Impact on Acoustic Correction of the Conference Hall at El Khalifa Cultural Center in Constantine

In Algeria, the field of acoustics has garnered limited attention from researchers, predominantly focusing on physical acoustics. Architectural acoustics, which deals with controlling auditory comfort and listening criteria within buildings, remains largely underexplored. The acoustic quality of spaces is a significant concern for physicists, architects, and researchers alike. The application of architectural acoustics in public spaces, such as conference rooms, greatly enhances the exchange of oral information and supports learning processes that require intensive verbal communication. This research aims to improve the acoustic quality of the existing conference room at the El Khalifa Cultural Centre in Constantine, Algeria. It has been noted that the centre experienced a reduction in reverberation time and sound diffusion due to an acoustic rehabilitation that introduced wall coverings of mixed panels composed of heavily perforated MDF and a layer of foam (8 cm thick). However, this rehabilitation resulted in the conference room becoming overly “deaf”, diminishing its acoustic quality. In order to address this issue, we proposed the installation of a network of six plywood reflectors, each 12 mm thick, placed on the ceiling of the room in the xy plane, with dimensions of 3×2.67 m2 each. Subsequently, the acoustic characteristics of the plywood reflectors were incorporated into the material database of the Olive Tree Lab Suite software to evaluate their impact on the room’s acoustic performance and the quality of sound diffusion. The results for reverberation time (TR60), clarity (C80), strength (G), definition (D50), and speech transmission index (STI) were highly satisfactory and aligned perfectly with the recommended values. Therefore, the acoustic correction significantly improved the listening conditions.