June_1970 — Page 10

LET ME TELL YOU WHAT HAPPENED THE OTHER DAY

LET ME TEAL YOU YIVÄT BAPPERED THE OTHER DAY

Normal speech can be understood distinctly through a wall with a transmission loss (TL) of less than 25 decibels.

If conditions are quiet loud speech can be understood through a wall with a TL of 30-35 db.

ARCHITECTURAL ACOUSTICS (19706

In the design of buildings, whether single structures or large, complexes, acoustics is often the cinderella of planning considera- tions. Architects who give little thought to the subject do their clients a disservice, says Mr. Ian Campbell, DA (Edin), ARIBA, MASA, lecturer in architecture at the Uni- versity of Hong Kong and a former partner in N.J. Pappas & Associates. For their guidance he has set out a simple checklist in a three-part series of articles for Far East Builder.

1. Initial design considerations

ARCHITECTS and builders tend to relegate acoustics to a minor role in planning and design. Often the subject is considered merely as a technique to be applied to a limited number of rooms within a building. Expert help is sought only when some acute problem commands the attention of the client or a consultant from the engineering facilities.

If the answer to the question, 'What are we doing to employ today's knowledge of acoustics in today's buildings?' is... 'Very little!' - then we are doing ourselves and our clients a disservice that should be remedied. Every building has acoustical prob- lems, just as it has structural, cooling, heating and electrical problems. Their best solution is a balanced compromise of design, budget and the limiting fac- tors. Unless we give acoustics the same

serious consideration we give the other technological aspects of building de- sign, we are not going to create the totally designed environment for human occupancy.

Over the last three decades there has been a major increase in noise sources and intensities, from trans- portation and from the equipment needed to meet the demands of our increasing standards of living. This noise increase coupled with the shift from heavy traditional to lightweight construction has made the problems of noise control greater today than ever before.

In planning for 'good acoustics', many aspects do not involve special techniques of construction but simply techniques of construction but simply the use of common sense; they can be reduced to rule of thumb and checklist format. I recall a very simple example

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given by a speaker at a housing sem- inar 'consider the mounting of door- bells in flats so that each occupant hears only his own bell, instead of wondering every time his neighbour's bell rings whether it could be his own.'

In this article and others to follow, I shall attempt to provide an easy acoustical checklist under these head- ings:

1. Initial planning and design considerations

2. Simple graphs and figures to check design requirements

3. Specification and super- vision

Initial planning

Acoustically, in planning a building we must understand the design criteria and the parameters it sets for our de- sign. Buildings are primarily for peo- ple. People require privacy, protection against intrusion and distraction, and good intelligibility of wanted sounds. People are remarkably adaptable and can accept a wide variation of con- ditions, but extremes are not accept- able.

'Too noisy' can be applied to any condition of our environment where one cannot talk comfortably to an adjacent person and be understood, where telephone use is difficult; in fact wherever occupancy is seriously dis- rupted.

'Too quiet' is where one can hear ones own breath or heartbeat; where the slightest form of noise from an- other source becomes an annoying distraction.

The architect's task is to create the

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Far East BUILDER, June 1970

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