ACOUSTIC ANALYSIS OF S.M.A.T 2-IN-1 LECTURE THEATRE IN THE FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE. COMPILED BY OTABOR OSARUMEN ARC/09/7424 SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF BACHELOR OF TECHNOLOGY (B-TECH) DEGREE IN ARCHITECTURE TO THE DEPARTMENT OF ARCHITECTURE, SCHOOL OF ENVIRONMENTAL TECHNOLOGY, FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE. Lecturer: Prof. Olu Ola Ogunsote APRIL 2014
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ACOUSTIC ANALYSIS OF S.M.A.T 2-IN-1
LECTURE THEATRE
IN
THE FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE.
COMPILED BY
OTABOR OSARUMEN
ARC/09/7424
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR
THE AWARD OF BACHELOR OF TECHNOLOGY (B-TECH) DEGREE IN
ARCHITECTURE
TO
THE DEPARTMENT OF ARCHITECTURE,
SCHOOL OF ENVIRONMENTAL TECHNOLOGY,
FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE.
Lecturer: Prof. Olu Ola Ogunsote APRIL 2014
TABLE OF CONTENT
1. 0 INTRODUCTION
1.1 ACOUSTICS AND ARCHITECTURE
1.2 JUSTIFICATION FOR THE STUDY OF ACOUSTICS
CHAPTER ONE
2.0 ARCHITECTURAL ACOUSTICS IN LECTURE THEATRES
CHAPTER TWO:
3.0 BUIDING DESCRIPTION
3.1 LOCATION
3.2 ARCHITECTURAL DESIGN
3.3 FINISHING MATERIAL
3.4 FACTORS AFFECTING ACOUSTICS
CHAPTER THREE:
4.0 SOURCES OF INTERNAL AND EXTERNAL NOISE IN 2-IN-1 LECTURE THEATRE
CHAPTER FOUR:
5.0 PERCEPTUAL ASSESSMENT OF THE ACOUSTIC CHARACTERISTICS OF THE 2-
IN-1 LECTURE THEATRE
6.0 REMEDIAL ACTIONS
REFRENCES
ABSTRACT
The study being carried out on the S.M.A.T 2 I 1 Lecture theater aims at giving a full acoustic
description of the hall in of the: Sources of noise into the building, the kinds of materials
employed in the construction of the building and the way these materials perform in acoustic
terms. Ways of improving the acoustics of the building are also to be suggested based on the
aspects mentioned above.
1.0 INTRODUCTION
ACOUSTICS is simply the physical quality of a space for performing music, which
involves mainly the study of the room acoustics and the control of noise; While ROOM
ACOUSTICS is concerned with the nature, properties and characteristics of sound in an
enclosed space, NOISE is simply an unwanted or damaging sound that interferes with what
people are trying to do or sound, which has an adverse effect on health or safety.
In order to be able to deal with the problems of noise in the Small Lecture Theatre, it would be
paramount to carry out an analysis of the nature, causes and effects of the noise. These findings
coupled with the knowledge of basic acoustics (the nature of sound and its physical properties.)
will be of significant importance in solving the noise related problems in the hall hence
providing a more conducive learning environment for the users.
1.1 ACOUSTICS AND ARCHITECTURE (acoustics in buildings)
The question of acoustics in lecture halls has been researched internationally in recent years.
Mackenzie, for example investigated the influence of poor acoustics on the students and
lecturers, in an important study in 1999.
Of course, good acoustics are important in lecture halls: the background noise must be
minimized and the room form and materials must be designed to support the acoustics in order to
provide high speech intelligibility.
1.2 JUSTIFICATION FOR THE STUDY OF ACOUSTICS
The study of acoustics in relation to buildings is necessary to incorporate the knowledge
gained into the early stages of design in other to achieve the following:
To create an acoustic friendly environment for all users including hearing impaired
individual.
To ensure maximum correspondence between individuals in an enclosed space without
disturbance form internal or external source of unwanted sound or noise.
To reduce to barest minimum the physiological and psychological effects of noise on
humans in the designed spac
CHAPTER ONE
2.0 ARCHITECTURAL ACOUSTICS IN LECTURE THEATRES
The use of a space is one of the main factors which influence its acoustics. The lecture theatre
is an example of a single performance space. It is an auditorium meant for speech alone and as
such, the individual speech sounds should be sufficiently distinguished for a speaker to be
readily understood. In spaces like these, it is relatively easy to achieve acoustic excellence
because the design can be focused around a single type/source of performance.
Acoustic excellence in a lecture theatre could be obtained by attaining very low levels of
background noise, which may go unnoticed by most people, but reduces their experience,
reducing clarity of sound. Studies have shown that a reduction in background noise significantly
reduces audience noise and eliminates the need for amplification of sound i.e. increasing signal
strength. When a lecture theatre is truly quiet, the speaker can use his entire dynamic range and
still be heard from every part of the building.
Before 1895, when a physicist William Clement Sabine was instructed by the corporation
of Harvard University to remedy the acoustical difficulties of the lecture room of the Fogg Art
museum, no actual quantitative measures had been brought to bear on characteristics of sound
such as reverberation, absorption, and sound transmittance. Sabine spent two years
experimenting on the Fogg lecture room and permanent changes were made. From this time
there followed a vocation for a new branch of physics; architectural acoustics.
In recent times, the importance of reducing noise levels has resulted in the development of
rules or guidelines stating the acceptable noise levels in different spaces. The problem of
acoustical problems in existing theatres has resulted in more demand for acoustic planning in
lecture theatres.
Fig 1a: Alumni Hall Carnegie Mellon University
An example is the Carnegie Mellon University alumni hall shown above, which was
originally built by Andrew Carnegie as an art gallery. It was plagued with acoustical problems
and while it was required to incorporate modern acoustic design it was also required that the
room’s historic heritage be preserved. As a solution, sound dispersing maple shells were used,
which complemented the restored hardwood floors. A skylight constructed of lexan pyramids
retains original day lighting and eliminates harsh echoes.
Another case study to show the effects of acoustic planning is the Plum High School
Auditorium in Plum PA. The acoustic planning was done by the sextant group. The goal was to
provide a natural acoustic environment that minimized the need for sound reinforcement, at the
same time preserving the structural and aesthetic vision as conceived by the architect.
Fig
1b: Interior
views of the
plum high
school
auditorium
showing
stage and
balconies
To accommodate 1700 seats, a large balcony had been designed which cast a significant
acoustic “shadow,” compromising the ability to hear in back rows. The original room geometry
also created a significant delay between direct and reflected sound, creating a disconcerting slap-
echo that further interfered with performances.
Sophisticated 3-D computer modelling was used to measure anticipated reflections and
calculate delays. Interactions between architectural space, surface and sound were considered,
adjusted and defined, revealing significant design opportunities that the architect was able to take
advantage of. Adjustments to the balcony positioning led to dramatic improvements in the room
acoustics. Further improvements came through strategic placement and angling of specially