Measuring Sound

Noise affects us everyday; at home, at leisure, during sleep, when traveling and at work. Taking an active role in making a room soundproof is not only soothing but could also yield noticeable health benefits. Below are a few things you should know about sound and how its measured.

STC stands for Sound Transmission Class. This is a method of gauging sound transmission loss through a wall. The American Standards and Testing Materials criteria is universally accepted by architects, designers, manufacturers, contractors and distributors of acoustical building products. The original acceptability of STC 34 walls must be reconsidered with the advent of increasing noise pollution.

While an STC rating is given in terms of points, the data is given in terms of decibels. A decibel, or dB, is a unit measure reflecting "how loud" a sound is. A sound pressure level of 0 dB represents the threshold of hearing in the most sensitive frequency range of a young, healthy ear, while the thresholds of tickling or painful sensations in the ear occur at about 120 to 130 dB.

Common Sound Noise Level Effect Hearing begins 0 dB 10 dB Just Audible Broadcasting Studio 20 dB Soft whisper 30 dB Very quiet Quiet Office 40 dB Light Auto Traffic 50 dB Quiet Speech 60 dB Noisy Restaurant 70 dB Intrusive Alarm Clock 80 dB City Traffic 90 dB Annoying Garbage Truck 100 dB Rock Concert 110 dB Very Loud Jet Taking Off 120 dB Thunderclap 130 dB Extremely Loud Air Raid Siren 140 dB Rocket Launching 180 dB Hearing loss

Now that we understand roughly what sound is and how sound is measured let's identify the two main noise problem problems that people are dealing with. Read: Identify Your Noise Problem.