Human society has a compulsive need to measure things. Distance, weight, time, space-we need everything neatly classified with a string of numbers followed by a cryptic acronym or label. Immediately upon birth, we assign babies with an Apgar score, ranging from 0-10, which measures their responsiveness. A smidgen of salt isn’t a colloquialism but precisely 1/2 a pinch or 1/32 of a teaspoon.
Sound is no exception. From the flutter of butterfly wings, to the deafening grind of a pneumatic drill and all those myriad whirs, clanks, drones and tones between-infinity doesn’t daunt us, humans. We have a uniform system to coral and classify sound. The two primary units of sound measurements are hertz (Hz) and decibel (dB). If you visualize sound as a continuous wave, hertz measures the frequency of each wavelength while decibel measures the size, or amplitude, of each wavelength. In layman’s terms, Hz indicates the pitch of the sound, for example, whether it’s a whistle or a thunder rumble; dB classifies the volume of the sound. 0 dB is the quietest sound heard by human ears, and with each increment of 3 dB, the sound doubles in its intensity or acoustic power. The social chatter in a restaurant would be 60 dB, while at ten units higher, the 70 dB of a vacuum cleaner would inhibit any easy conversation.
dBA is a combined calculation of decibel and hertz and is often used to describe noise levels instead of just plain dB. This is because sometimes it’s the frequency and not only the volume, that we find incredibly bothersome. Think about the urgent intensity of an emergency vehicle siren: that wail and honking isn’t merely loud but is pitched to really cut through the background noise and enter our eardrums.
An A-weighting is when decibel scale readings have been adjusted to take the varying sensitivity of the human ear into account for different frequencies of sound. Regulatory noise limits are specified in terms of dBA since it is better linked to understanding the risk of noise-related hearing loss. A-weighting adjustment ensures low and very high-frequency sounds are given less weight than on a standard decibel scale. For this reason, electronic appliances are often measured in dBA.
Hush Goes the Quilo
When we designed the Quilo 3in1 Evaporative Air Cooler, we wanted a unit that would have cooling power but also be quiet and comfortably unobtrusive. On its sleep setting, the Quilo 3in1 measures a sweet 24 dBA, which is compared to the whispering sound of rustling leaves. If you can handle a volume of 53 dBA, or the equivalent of a quiet urban neighborhood, then that would be the Quilo on turbo mode. And for those of you wanting moderation, there are three incremental fan settings between these ranges. Keep cool and keep comfortable-that’s our motto!