01_acoustics intro.pdf

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BUILDING UTILITIES ACOUSTICS

WEEK 1


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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.


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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

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BOOK V OFDE ARCHITECTURA

history


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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.

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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.

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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

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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.

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history

THE ODEON THEATER : A ROMAN THEATER IN DOWNTOWN AMMAN, JORDA


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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.


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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


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history

One, was the diminishing loudness or intensity of theboth with distance and according to the amount oabsorbed by the rooms surfaces and contents.


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history

The second, was the increasing confusion of soundcaused by reflections from the rooms surfaces.


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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


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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


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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.

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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,


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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


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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.


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history

becfirstdesaccscieaco

Adacotimtheas osouconwo

BOSTONS SYMPHONY


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END OF THEPRESENTATION


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What is a Sound? something we hear as a result of vibration of a

created by compressed and expanded air pressufluctuations.

INTRODUCTION


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Sound theory


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Sounds are everywhere!

There are:

Airborne sounds: The medium is Air

Structure-borne sounds: The mediumConcrete, steel, wood, glass and combinations of

Sound theory


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01_acoustics intro.pdf