What is the equivalent sound level?

October 27, 2025

Nyquist Team

Basics of acoustics

A constant sound level over time that produces the same energy effects (has the same square of acoustic pressure) as a time-varying measured signal.

It is calculated according to the formula:

Where:

T – assessment time;
LAmi – the average level of sound A occurring during the time when the noise can be considered stable;
ti – the time during which the level of sound A is stable and equals LAmi;
n – the number of time segments ti in the time interval T;

Thanks to this averaging, the level of unstable noise can be compared with the level of stable noise. The equivalent sound level is a single-number parameter that allows assessing the acoustic climate in a given place. For this reason, in standards defining the permissible noise level in a given area, this parameter is used.

Nyquist Team

The Nyquist team is a group of enthusiasts in acoustics, design, and technology who combine engineering knowledge with aesthetic sensitivity every day. We create solutions that improve acoustic comfort and give spaces a unique character. On the blog, we share our experiences, knowledge, and inspirations drawn from our daily work on projects carried out across Poland and abroad. We believe that good acoustics is not just a technique – it’s a way of creating spaces where one simply enjoys being.

Nyquist Team

Nyquist Team

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