The Decibel: An Important Term in Lab Safety

We talk a lot about noise in this blog, for very good reason: A quieter lab is a safer lab. Lab safety requires being able to easily hear and understand your fellow lab workers, so we engineer our dedicated lab furniture to make your lab quieter.

In order to talk about sound and noise, however, you need the proper terminology. The decibel, often abbreviated as dB, is a frequent term in posts where we talk about noise safety in the lab. Let’s take a closer look at the humble decibel—where it came from, what it means, and why it’s so ubiquitous in discussions about noise and lab safety.

History of the Term ‘Decibel’

Where does the term “decibel” comes from? Modern efforts to measure sound volume originated in the need to quantify signal loss over telephone lines and telegraph cables. Early terms included MSC (for miles of standard cable) and TU (for transmission unit).

Eventually, the Bell System renamed the TU as the decibel, classifying it as one-tenth (hence the “deci”) of a “bel” (which was named after Alexander Graham Bell, inventor of the telephone—The full scientific name of the bel is the Alexander Bell which explains why the B in “dB” is capitalized).

Understanding the Decibel

In the National Bureau of Standards Yearbook of 1931, decibel was defined as follows:

The decibel may be defined by the statement that two amounts of power differ by 1 decibel when they are in the ratio of 100.1 and any two amounts of power differ by N decibels when they are in the ratio of 10N(0.1). The number of transmission units expressing the ratio of any two powers is therefore ten times the common logarithm of that ratio.

The bel signifies the logarithm of a 10:1 ratio between two power quantities (the ratio of measured power to reference power), or the logarithm of a ratio between two field quantities (the ratio of the squares of measured field and reference field) of √10:1.

The Spread of Decibel Usage in Addressing Noise Safety Situations

Over the decades since, the decibel has become a common standard of measurement for a variety of situations, including assessing noise safety for labs and other workplace environments. The decibel measures acoustics (as a unit of sound pressure), perception (as a measurement of intensity for both sound and light), optics (to measure loss over an optical link), and electronics (to measure amplitude ratios).

As we’ve noted previously, the Occupational Safety and Health Administration’s noise safety standards are measured in decibels. While the International Committee for Weights and Measures declined to include the decibel in the International System of Units, it is recognized by other international bodies, including the International Electrotechnical Commission and the International Organization for Standardization.

Connecting the Decibel with Lab Safety

In terms of lab safety, fewer dBs of noise is an important goal. That is where our dedicated lab furniture can make a big difference. Like the decibel itself, human perception of sound—especially sounds that intensify annoyance or hinder efficiency—seems to increase almost exponentially.

The sound of vacuum pumps and other mass spectrometry equipment can quickly contribute to noise safety hazards in the lab, especially when layered over the sounds of fume hoods, air conditioning and handling equipment, and essential conversations. However, our IonBenches are guaranteed to produce a 15 dBA reduction in roughing-pump noise. To find out other ways our dedicated lab furniture can enhance your lab’s safety, get in touch with Tim Hawkins at tim.hawkins@farhawk.com or 888-669-1233.

PS: Do you know why a letter like “A” often follows “dB”? Stay tuned for our next post, which will explain dB suffixes, as well as various ways to use the dB measurement.