7/24/2019 01_acoustics intro.pdf
1/25
BUILDING UTILITIES ACOUSTICS
WEEK 1
7/24/2019 01_acoustics intro.pdf
2/25
INTRODUCTION
WHAT IS ACOUSTICS?Is defined as the science that deals with the prod
control, transmission, reception, and effects of so
defined by Merriam-Webster) Is the science sound.
7/24/2019 01_acoustics intro.pdf
3/25
EARLY RESEARCH IN ACOUSTICS
PHYTAGORAS ARISTOTLE VITRUVIUSHARMONIC OVERTONE FOUND OUT A VERY WROTE A TREATIES AB
SERIES ON STRINGS GOOD EXPRESSION ACOUSTIC PROPERTIE
OF THE NATURE OF THEATERS INCLUDINGWAVE MOTION
DISCUSSION OFINTE
ECHOES REVER
THE BEGINNING OFARCHITECTURAL
history
7/24/2019 01_acoustics intro.pdf
4/25
BOOK V OFDE ARCHITECTURA
history
7/24/2019 01_acoustics intro.pdf
5/25
BOOK V OF DE ARCHITECTURA VOICE IS A FLOWING BREATH OF AIR, PERCEPTIBLE OT THE HEAR
CONTACT.
It moves in an endless number of circular rounds, like the inincreasing circular waves which appear when a stone is thrown inwater, and which keep on spreading indefinitely from the centre
interrupted by narrow limits, or by some obstruction which prevenwaves from reaching their end in due formation.
When they are interrupted by obstructions, waves, flowing back, break up the formation of which follow.
history
7/24/2019 01_acoustics intro.pdf
6/25
BOOK V OF DE ARCHITECTURA IN THE SAME MANNER, THE VOICE EXECUTES ITS MOVEMEN
CONCENTRIC CIRCLES.
The voice not only proceeds horizontally, but also ascvertically by regular stages. The first wave, when there is no
obstruction to interrupt it, does not break up the second or tfollowing waves, but they all reach the ears of the lowest anspectators without an echo.
history
7/24/2019 01_acoustics intro.pdf
7/25
BOOK V OF DE ARCHITECTURA Hence the ancient architects, following in the footsteps o
perfected the ascending rows of seats in theatres from theinvestigations of the ascending voice, and, by means of thcanonical theory of the mathematicians and that of the m
endeavoured to make every voice uttered on the stage cgreater clearness and sweetness to the ears of the audien
history
7/24/2019 01_acoustics intro.pdf
8/25
BOOK V OF DE ARCHITECTURAAscending seats in ancient theaters as designed to prevent deterioration of sound and also recommended bronze vesseappropriate sizes be placed in theaters to resonate with thefifth and so on, up to the double octave, in order to resonatmore desirable, harmonious notes.
history
7/24/2019 01_acoustics intro.pdf
9/25
history
THE ODEON THEATER : A ROMAN THEATER IN DOWNTOWN AMMAN, JORDA
7/24/2019 01_acoustics intro.pdf
10/25
history
During the eighteenth century the importance of roacoustics was further heightened with the inventionnumber of musical instruments such as the harpsichfortepiano, and the growing popularity, in elite circlleast, of chamber music.
7/24/2019 01_acoustics intro.pdf
11/25
history
It was already well-understood that the size of a room and threflectivity of the walls, floor and ceiling affected the intelligibspeech and music, and that two different effects were at work
7/24/2019 01_acoustics intro.pdf
12/25
history
One, was the diminishing loudness or intensity of theboth with distance and according to the amount oabsorbed by the rooms surfaces and contents.
7/24/2019 01_acoustics intro.pdf
13/25
history
The second, was the increasing confusion of soundcaused by reflections from the rooms surfaces.
7/24/2019 01_acoustics intro.pdf
14/25
history
THREE DIFFERENT TYPES OF SURFACE THATBE USED, CAN BE COMBINED:
STONE OR PLASTER: CAN ENHANCE THE REFLE
WOVEN FABRICS; TAPESTRIES OR CURTAINS:
CAN ABSORB SOUND
TIMBER PANELING: WAS THE INTERMEDIATE OF T
7/24/2019 01_acoustics intro.pdf
15/25
history
OTHER DESIGN FACTORS: The distance between speaker or instrument, a
directness of the sound path.
The other consideration was the distance betwthe stage and the listener.
It was generally agreed that an actor speaking in a normal voice could be uclearly up to a distance of about 18 metres, and with difficulty up to about
7/24/2019 01_acoustics intro.pdf
16/25
TIMELINEEARLY 18TH CENTURY Design rules for theatre acouswere not very and there were many acoustic disa
SECOND HALF OF 18TH CENTURY saw a boom in thebuilding in the major cities, and designers generallearned from the acoustic disasters of the early ce
LATE 18TH CENTURY it was common practice to useceiling or soffit.
history
7/24/2019 01_acoustics intro.pdf
17/25
history
TIMELINE EARLY 19TH CENTURY Design rules for good acoustic
widely used not only in theatres and auditoriums bin chambers in which politicians and legislatorscongregated,
7/24/2019 01_acoustics intro.pdf
18/25
INTRODUCTION
WHAT IS do we mean by
architectural acoustics?
The properties or qualities of a room or buildingdetermine how sound is transmitted in it.
Can be about achieving good speech intellig
a theatre, restaurant or railway station, enhancingquality of music in a concert hall or recording studsuppressing noise to make offices and homes morproductive and pleasant places to work and live i
7/24/2019 01_acoustics intro.pdf
19/25
history
Wallace Clement Sabine
(June 13,1868January 10, 1919)
THE FATHER OF ARCHITECTURAL ACOUSTICS
was an American physicist who founded the fieldof architectural acoustics.
Sabine was acoustical architect of Boston'sSymphony Hall, widely considered one of the twoor three best concert halls in the world for itsacoustics.
7/24/2019 01_acoustics intro.pdf
20/25
history
becfirstdesaccscieaco
Adacotimtheas osouconwo
BOSTONS SYMPHONY
7/24/2019 01_acoustics intro.pdf
21/25
END OF THEPRESENTATION
7/24/2019 01_acoustics intro.pdf
22/25
What is a Sound? something we hear as a result of vibration of a
created by compressed and expanded air pressufluctuations.
INTRODUCTION
7/24/2019 01_acoustics intro.pdf
23/25
Sound theory
7/24/2019 01_acoustics intro.pdf
24/25
Sounds are everywhere!
There are:
Airborne sounds: The medium is Air
Structure-borne sounds: The mediumConcrete, steel, wood, glass and combinations of
Sound theory
7/24/2019 01_acoustics intro.pdf
25/25