Hany Hossam Eldien

Working in Architecture design studios environment requires various activities. Interaction, communication and meetings could affect the speech intelligibility and the speech privacy conditions. Students Areas with a more silent environment are needed with a minimized level of distraction from surrounding activities, while teamwork and discussion areas with a high level of interaction need a good speech intelligibility. One of the more important elements which can improve the open spaces acoustical conditions is the partitions between workstations.The main purpose of this work is to evaluate the acoustical performance of four partitions types in open plan offices; 1.10m two sides partition height, 1,50m front side partitions, 1,50m one side partitions and 1.50 two sides partitions. This Study was conducted in the College of Architecture, Imam Abdulrhman Bin Faisal University, KSA. Based on ISO 3382-3, Speech Transmission Index, STI in the nearest workstation, Distraction distance rD, privacy distance rP, A-weighted background noise level L,A,B and A-weighted SPL of speech at 4 metres L,A,S,4m have been measured. It was found that the best results can be obtained by 1.50m front side and 1.50m two sides partitions.

This chapter presents a detailed analysis to identify the best Mihrab (prayer niche of Imam) geometry with respect to acoustic performance of mosques. Mihrab geometry has an impact on daily prayer recitation and orders, as the Imam (prayer leader) faces this semicircular shape. Sound pressure level (SPL) has been simulated to compare different well-known designs and geometries of Mihrab by ODEON. A typical mosque in an educational campus was considered for the study, and it is found that Safavid Mihrab geometry has the best performance followed by Chinese, Mughal, and Tulunid Mihrab geometries, while the worst performance is found in Almoravid Mihrab geometry. This study obviously guides the mosque designers to choose the appropriate Mihrab geometry with regard to the acoustic performance.

Acoustic diffusers are important components in enhancing the quality of room acoustics. This paper investigates a new type of 2D diffusers obtained by the Cymatics phenomena. Cymatics is the study of sound and vibration made visible, typically on the surface of a plate, diaphragm, or membrane. Four shapes of the diffusers were designed by the Cymatic shapes and modeled by using a quadratic residue sequence. The polar response of the diffusers was measured using DIRAC software. Polar response results were generally consistent with expectations. This type of diffusers can generate a uniform polar response over the frequency range we are interested in (400–4000 Hz). It is found that this type of acoustic diffusers can be used to maintain the acoustic energy in a room and at the same time can treat unwanted echoes and reflections by scattering sound waves in many directions.

Acoustic diffusers are important components in enhancing the quality of room acoustics. This paper investigates a new type of 2D diffusers obtained by the Cymatics phenomena. Cymatics is the study of sound and vibration made visible, typically on the surface of a plate, diaphragm or membrane. Four shapes of the diffusers were designed by the Cymatic shapes and modeled by using a quadratic residue sequence. The polar response of the diffusers was measured using DIRAC software. Polar response results were generally consistent with expectations. This type of diffusers can generate a uniform polar response over the frequency range we are interested in (400Hz- 4000Hz). It is found that this type of acoustic diffusers can be used to maintain the acoustic energy in a room, and at the same time can treat unwanted echoes and reflections by scattering sound waves in many directions.

Noise in cities has increased in the past decades, due to a growing urban development. In the last century, population movement to the greater cities, disorder planned city development and increase of the motor vehicle in the traffic have been produced noise pollution and other environmental problems. Management and reduction or urban noise has been called for in urban development plans. Noise community ordinances have been approved at national and local levels in various countries of the world. They usually establish noise limits for various activities and zones, according to the land uses, and define the basis of noise management strategies. It is required to draw noise maps, as a noise management tool, to be integrated in the land use plans and to be used as a basis for noise reduction plans where the noise levels exceed maximum prescribed levels. Noise mapping in large urban areas presents methodological and financial hindrances due to both the technical complexity involved and to the amount of human and technical resources that are necessary. In some cases, noise pollution can be more important than the other environmental problems. The most important factor which affects the noise pollution is the mistakes taken place during the application of the city plans due to different political and social factors. In this investigation, effect of the application of city plan (use of ideal usage on the road and building areas, and ratio between buildings and green areas) on noise pollution was studied. Geographical information systems (GIS) plays an important role in the noise mapping. Noise pollution map of Suez city center in Egypt using GIS has been presented with the 400 sampling point selected on main roads in the city centre. A marked effect of increasing building levels on indoor noise pollution has been also found near the main roads. Problems are highlighted and discussed, especially those regarding the optimization of data quality and data management, the accuracy of the results and the benefits for the acoustical environment.

Roadway noise is the most important example of a linear noisesource, since it comprises about 80 percent of the environmental noise exposure for humans worldwide. Due to the complexity of the variables, a line sourceacoustic model is realized by a computermodel . In this paper we propose a new approach system based upon Schröder's quadratic residue diffuser modeling for modeling a linear traffic source. 1/10th scale model has been used to simulate the traffic noise propagation in front of the building façade and for a free field. The line source directivity is made quasi‐uniform in the aperture angle of interest. The line source directivity measurements were made using a 1/4" microphone Larson Davis type 2530. The sequence of the quadratic residue diffusor is calculated following the Schröder's modulo formula and with 1.60m length, 0.14m height, and 0.11m width. The line source has also been weighted by a full‐size equivalent normalised traffic noise spectrum according to the French standard NF EN 1793‐3.