Ú Explain Sound behaviour including reflection,
absorption, energy density, sound decay and reverberation. Ú Learn how to design an acoustic room and its design considerations. Ú Learn what is Electroacoustics.
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Wave Theory and Normal Modes × ñhe concept of a sound ray and the geometrical study of sound ray paths play an important role in the design of large rooms and auditorium, enabling troublesome echoes and flutter effects to be detected and dealt with at the design stage. × A limitation of the geometrical approach is that usually only primary and possible secondary reflections can be studied before the sound ray being followed becomes 'lost' in the reverberant sound field and, in most enclosures, it is restricted to frequencies of 500 Hz and above.
Ãsing Geometric Acoustics × Statistical methods are useful at the earliest stages of
design, however, as more and more geometric information becomes available, why not use it. × As enginneers, we need to be able to determine not
only how much absorber to use, but what type of absorber and where to put it. ñhis is where the consideration of reflected sound rays can be quite useful.
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O 0or many years the reverberation time was the only real objective measure of the acoustic performance of an auditorium. 0or many architects, even today, it still is. However, there are many more aspects to sound behavior in rooms. × arly Decay Time × Clarity and Definition × Spatial Impression × Speech Intelligibility
O arly Decay Times × ñhe reverberation time, as discussed earlier, refers to the time taken for the reverberant component of an enclosure to fall by 60 dB after the source is abruptly switched off. In an ideal enclosure this decay is exponential, resulting in a straight line when graphed against Sound Level. Studies of actual auditoria, however, show that this is not always the case. × Research (Kuttruff 1973) has shown that it is the initial portion of the sound decay curve process, which is responsible for our subjective impression of reverberation as the later portion is usually masked by new sounds. ño account for this, the Early Decay ñime (EDñ) is used. ñhis is measured in the same way as the normal reverberation time but over only the first 10 - 15 dB of decay, depending on the work being referenced.
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Outline of Acoustic Requirements for Good Sound × ñ × ×
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ñhere are essentially three types of loudspeaker system; w
Also known as a high level system, this is essentially a single cluster of loudspeakers located near the source. Such a system gives maximum realism as the amplified sound, whilst increasing loudness and clarity, is still associated with the original source.
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× Individual Case Analysis study
to be submitted next meeting × ñHANK YOU 0OR YOUR KIND AññENñION
