Noise Exposure Level

Overview

Engineering reference data for Noise Exposure Level in acoustics.

Key Formulas

Speed of Sound

$c = \sqrt{\gamma R T}$

Speed of sound in an ideal gas.

Sound Level

$L = 10 \log_{10}(I/I_0)$

Decibel level.

Wavelength

$\lambda = c / f$

Wavelength = speed / frequency.

Variables

Symbol	Description	Unit
$c$	Speed of sound	m/s
$L$	Sound level	dB
$\lambda$	Wavelength	m
$f$	Frequency	Hz

Example Calculation

Consider a worker exposed to 100 dB for 5 minutes and 94 dB for 30 minutes during an 8-hour workday. The maximum allowed exposure times are 15 minutes for 100 dB and 60 minutes for 94 dB.

The daily noise dose $D$ is calculated as:

$$D = \left( \frac{5 \text{ min}}{15 \text{ min}} + \frac{30 \text{ min}}{60 \text{ min}} \right) \times 100\% = 83\%$$

The 8-hour Time-Weighted Average (TWA) is then:

\text{TWA} = 10 \log ## References - [Original Source](https://www.engineeringtoolbox.com/noise-exposure-level-d_718.html)