E2S de-mystify the decibel

Warning signal manufacturer publishes new information guide to measuring sound levels in dB

E2S Warning Signals, one of the world’s leading independent manufacturers of high-performance audible and visual signals for commercial, industrial, marine, onshore and offshore hazardous locations, have published an educational guide that seeks to ‘de-mystify’ the dB (decibel) – one of the most common units in engineering, yet also one of the most confusing.

The main difficulty in comprehending dB measurements is that it is a log-linear scale, which, while it is very useful in representing very large differences in a user-friendly way, also compresses the scale.

Sound is defined as any pressure variation that can be heard by the human ear. The ‘threshold of hearing’ is defined as 0dB, whilst the threshold of pain is around 130dB – a scale that can be readily understood.

However, the power difference between these two sound levels is actually 10,000,000,000,000:1 (ten million million to one).

The new guide sets sounder output levels in context with a number everyday examples. It also discusses the effect of frequency on perceived loudness and includes some rules of thumb for system designers who are specifying the output and location of warning sounders to provide the desired sound levels as part of a warning system.

The guide, ‘Sound basics: measuring power in dB’, can be found in the Information Library section on the E2S website.