Unveiling the Secret of Background Noise: The Hidden Disturbance of Silence
What is Background Noise? The Hidden Noise in Even the Quietest Places!
Background noise refers to the persistent sound present in an environment when no specific sound is being measured. In other words, it is the subtle yet significant ambient noise that exists unnoticed. For example, when measuring a car’s idling noise (70dB) in a semi-anechoic chamber, the ambient noise of the room before placing the car (15dB) is considered background noise. Such background noise can greatly affect the accuracy of acoustic measurements.
Don’t Overlook the Impact of Background Noise!
If the background noise level is at least 10dB lower than the target noise level, its effect can be ignored. However, if the difference is less than 10dB, corrections for background noise become necessary. For instance, if a factory machine’s operating noise is 85dB and the background noise is 80dB, the difference is only 5dB. According to JIS Z 8731, in this case, the noise is estimated at 83dB, subtracting a correction value of 2dB. Understanding background noise is essential for accurate noise measurement.
Key Points for Measurement Considering Background Noise
- Aim for a 10dB Difference: A difference of more than 10dB between background noise and the target noise eliminates the need for corrections. This is the ideal scenario.
- Turn Off Surrounding Equipment: Minimize background noise during measurements by temporarily stopping nearby equipment.
- Be Cautious of Fluctuating Background Noise: If background noise fluctuates, it may become impossible to apply corrections, so ensure a stable measurement environment.
Control Background Noise for Accurate Measurements!
Understanding background noise is critical for accurate noise evaluation and effective soundproofing solutions. Don’t overlook “hidden noise”, implement proper measures, and achieve a more precise acoustic environment!