Two good benchmarks to remember are that at arms' length away: Focusing on the first three columns, we can see that at 0 decibels, we are just beginning to be able to hear a sound and at 120 decibels or more, sound begins to be physically painful. Next to that is a typical decibel value (A-weighted sound level, abbreviated dB(A)) of that sound or environment. The next column shows a subjective description of how that sound would be perceived by a typical listener. The following table lists sound sources and sound environments with which you may be familiar. The vast extent between the quietest sound we can hear and the loudest sound we can withstand is truly amazing. The first thing that should be appreciated is that we humans can hear a remarkably huge range of sounds. What is a decibel, often seen as 'dB' or 'dB(A)?' How does one decibel value compare to another? In this post, I will start with real-world examples of decibels in action, provide some context and rules of thumb, and work up to the formal definition, which is not really necessary in order to gain a working knowledge of decibel sound levels. Lastly, if you attempt to seek out a definition of a decibel, you will likely find one that is written for or by an engineer, which may or may not be helpful. Also, there is a general lack of familiarity with how decibel sound levels are related to how loud a sound is perceived.

For example, if a bird is singing its song at a sound level of 60 dB(A) and another one joins in at the same volume, then the total sound level is not 120 dB(A), it is actually 63 dB(A). USSI Director of Industrial Acousticsĭecibels can cause confusion.

Scale for combining decibels