الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 193 |  |  |
| | | from | 193 | | |
Abstract
Architectural Acoustics is one of the most important architectural sciences, which
must be put into practice in the built environment. In today’s architectural environment,
good acoustical design is not a luxury, but it is a necessity. Smith (2011) states that
Acoustics has a strong impact on the learning quality in educational facilities for both
instructors and students. Experts believe that as many as one-third of all students miss up
to 33 percent of the oral communication that occurs in the classroom (Nixon, 2002).
Although the science behind sound is well understood, using that science to create
desired acoustical performance within a specific building or room is complex. There is no
single acoustical solution that can be universally applied to building design. Each built
environment offers its own unique set of acoustical parameters (Smith, 20 11). There is a
lack of acoustic standards for educational facilities in Egypt, especially university
classrooms, resulting in a very bad acoustical quality in the existing spaces. Excessive
noise in the classroom is an unacceptable barrier to learning, which our society can ill
afford (Sutherland, 2001).
This thesis aims at studying the history and basics of architectural acoustics and
acoustic performance standards in different countries such as (ANSI-SI2.60, 2010, BB93,
2003), and then using those standards to evaluate the acoustical quality in classrooms at the
city of Alexandria through an empirical study. The study is emphasized on different types
of at three universities in Alexandria: Alexandria University, Arab Academy for Science,
Technology and Maritime Transport (AASTMT) and Pharos University in Alexandria
(PUA). Three types of classrooms were investigated: drawing studios, lecture halls and
small classrooms. Physical parameters of the studied classrooms were first taken, then the
acoustic evaluation process was carried out by three methods; using B&K2250 Sound
Level Meter for physical measurements, Computer modeling using Odeon acoustic
prediction software and finally mathematical calculations using Sabine and Eyring
formulae for predicting reverberation time. The empirical study results were then
compared to the recommended values by the previously mentioned standards. Because of
the lack of instruments, the study focused on sound levels, background noise levels,
reverberation time and Signal-to-Noise ratios (SIN).
The results of the empirical study prove that there is a lack of acoustic performance
awareness in the city of Alexandria. Most of the studied classrooms did not meet the
recommended values of maximum noise levels, reverberation times and signal-to-noise
ratios. The main problem in of the studied classrooms is using inappropriate finishing
materials, which provide high sound reflections, and thus very high reverberation. In the
conclusions and recommendations section, some proposals were suggested to improve the
acoustical quality of some classrooms by replacing highly reflective materials by
absorptive materials. Predictions have shown a significant acoustic improvement. A
comparison between the three evaluation methods was studied in this chapter.