Noise Reduction Rating Calculator

Formula

The formula to calculate the Reduced Noise Level (RNL) is:

\[ \text{RNL} = \text{NL} - \left(\frac{\text{NRR} - 7}{2}\right) \]

Where:

\(\text{RNL}\) is the reduced noise level at the ear (dB)
\(\text{NL}\) is the ambient noise level (dB)
\(\text{NRR}\) is the Noise Reduction Rating of the hearing protection (dB)

Noise Reduction Rating Definition

Noise Reduction Rating (NRR) is a unit of measurement used to determine the effectiveness of hearing protection devices to decrease sound exposure within a given working environment. The higher the NRR number associated with a hearing protector, the greater the potential for noise reduction.

Example Calculation

Let's assume the following values:

Ambient noise level (NL) = 100 dB
Noise Reduction Rating (NRR) = 30 dB

Using the formula:

\[ \text{RNL} = 100 - \left(\frac{30 - 7}{2}\right) = 86.5 \text{ dB} \]

The Reduced Noise Level (RNL) is 86.5 dB.