What is it and what is the difference between dB and dB(A)?

In the world of ventilation systems, the terms "dB" and "dB(A)" are often used. These two terms are used to measure sound pressure levels. While they share similarities, they are used in different contexts and have differences that are important to know.

dB (decibel) is a unit of measurement for sound pressure that indicates its level. It is used to measure the absolute strength of a sound without taking into account the peculiarities of human hearing. dB is a linear scale, which means that each 10 dB increase corresponds to a 10-fold increase in sound pressure. The higher the dB value, the louder the sound.

However, human hearing perceives sounds of different frequencies differently. Human sensitivity to low and high frequencies is not the same. To account for this difference, the dB(A) weighing scale is used.

dB(A) is a scale that takes into account the sensitivity of human hearing to different frequencies. It is most commonly used to measure noise levels because it reflects how people perceive sound. The dB(A) values are measured using a filter that reduces the influence of low and high frequencies on the measurement. This allows for a more accurate assessment of the noise level that affects people.

Thus, the difference between dB and dB(A) is to take into account the sensitivity of human hearing to different frequencies. dB measures the absolute sound pressure level, while dB(A) takes into account the human perception of sounds. When measuring noise levels in industrial environments, both indicators are often used to obtain a complete map of the noise environment.