Before trying to solve a specific noise problem, it’s important to understand the nature of the unwanted noise so that you can quantify it as well as establish an acceptable sound level. The difference between these two values is the degree of sound control you will need to achieve with your door opening.
Here’s a brief overview of the science of sound and its measurement, beginning with a few important definitions:
Sound is best described as vibrations in air moving in waves. The rate of sound pulsations measured in cycles per second is called frequency, also known as hertz (Hz). The range of human hearing is considered to be 20 to 20,000 Hz.
Sound pressure levels are measured in decibels or dB. The scale of measurement used to simulate sound across the audible frequency range is denoted as dBA. The human ear perceives changes in loudness caused by even small changes in sound levels. Each 10 dB increase doubles the sound reception, and the corresponding discomfort.
In this comparison of sound pressure levels and loudness sensations, one can see the impact of exposure to various sources of sound and the respective sound pressure level from 0 dBA to 130 dBA, as well as the expected sensation. For instance, 0 dBA is the threshold of audibility, with a whisper measured at 10 dBA in a soundproof room producing a very faint sensation. One can experience a moderate sensation in a noisy home or a general office, which would produce a sound pressure level of 60 dBA. A noisy factory would create a very loud sensation at 100 dBA, and a deafening sensation would be the outcome of exposure to the sound of thunder, artillery or an elevated train at 120 dBA. Jet aircrafts can produce 130 dBA, with the sound even causing physical pain.
To find a solution to mitigate noise in a practical application, Allegion would first need to understand how sound is transmitted from its source through a barrier. Every barrier is rated for its ability to inhibit or block sound. A comparison of barriers would equip Allegion with the necessary information to examine the role of gasketing systems in optimising the performance of doors that function as sound barriers.
Allegion helps customers navigate their toughest security challenges with a diverse product range comprising of residential and commercial locks, door closers and exit devices, door seals, steel doors and frames, to access control and workforce productivity systems.