To investigate the frequencies (200 Hz – 6300 Hz) dependence of the sound absorption co-efficient for Porous absorber material sample and Hardboard (helmholz absorber) in front of Porous sample using Standing Wave tube for absorption coefficient. Laboratory Experiment
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Sound Absorption Coefficient
I am writing to provide a review and report on Sound Absorption Coefficient Laboratory Experiment.
Background, Relevance and Aim:
Sound waves are produced by continuous vibration which can travel through the air or any other medium, sound can be heard when reach human ear or any other sound receiver, sound is form of energy and the more energy in a sound the louder it is, however there are many factors which determine the loudness of the sound such as sound intensity and sensitivity of the receiver (human air).
When sound is undesirable, it affects human acoustic comfort and then is said to be noise, human ear can respond to minute pressure variations in the air if they are in the audible frequency range, roughly between 20Hz -20kHz.
In most noise consideration, The A –weighted sound level is used, this scale found to be appropriate because the human ear does not respond uniformly to sounds of all frequencies, A-weighted sound simulates the response of human ear toward incident sound.
The absorption co-efficient of a sound is defined as the ratio between the energy absorbed by the sample and the total energy strikes the sample, that specific material co-efficient determines how good a material is, in sound absorption, sound absorption co-efficient vary from material to another material . PDF.
• To investigate the frequencies ranges (200Hz – 1000 Hz) dependence of Poro...
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... time on podium is significantly lower than the hall early decay, the reason of that is the proscenium structure on the podium, however musicians response from the questionnaire to it as that is not a problem.
Podium Early Decay Time V Hall Early Decay Time
The measurements and investigations presented show that this hall has a very good acoustic condition, although the layout has some defects, the deep rear balcony is an issue in addition to the proscenium podium.
Never the less, measurements taken and listening experience have given that the acoustic conditions in the hall are very good, and the weakest part is the back of the rear balcony, however it is still acceptable and there are no major problems in the Balshoi Hall of the P.I. Tchaikovsky Conservatory in Moscow.
www.akutek.info, 2010, available at http://www.akutek.info/Papers/HM_Moscow_Hall.pdf.
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