Architectural acoustics is the scientific field that aims to understand and control the propagation of sounds in buildings. Acoustic tests are done according to the methods recognized by ASTM (American Society for Testing and Materials).
Impact noises (IIC) are measured using a normalized impact noise generator also called Tapping Machine. This device is calibrated to provide the same impact on the ground and to emit sounds at the same frequency, regardless of manufacturer. It is comprised of aligned hammers of equal mass successively striking the ground from a determined height and at a precise speed. Under test conditions, the machine is placed on the floor that one wants to study and a sonometer is installed in the room below and captures the sounds emitted by the tapping machine. Then, the collected data is compiled according to the principles issued by the ASTM standards.
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The analysis gives us a final result, expressed in a sound reduction index, example IIC 58. The latter indicates the amount of noise that the complete floor/ceiling structure has attenuated. So, the higher the result, the greater the acoustic efficiency.
Although acoustics is a precise science, the acoustic performance of a building remains difficult to predict. Each floor/ceiling building assembly vibrates at different frequencies and the slightest change in the density of the materials used, the quality of the contact between them or the order in which they are positioned for sure changes the result!
If you live in a problematic situation with your neighbor over hearing him walking at any time of day and night, it is best to contact an acoustic expert to better understand the causes. The AcoustiTECH team can help you find efficient solutions for impact noises and find peace of mind.