Room Absorption Sound

Overview

Engineering reference data for Room Absorption Sound 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

Room Absorption Characteristics Table

The following table summarizes room characteristics, typical reverberation time ranges, and mean sound absorption coefficients for different room types.

Mean Sound Absorption Coefficient Calculation

For more accurate values, the mean sound absorption coefficient ($\alpha_m$) should be calculated using the weighted average of individual surface absorption coefficients:

$$\alpha_m = \frac{\sum_{i=1}^{n} \alpha_i S_i}{\sum_{i=1}^{n} S_i}$$

Where:

• $\alpha_i$ is the sound absorption coefficient for surface $i$,
• $S_i$ is the area of surface $i$,
• $n$ is the total number of surfaces.

This coefficient directly influences reverberation time ($T_a$), with higher $\alpha_m$ leading to shorter reverberation times and a softer acoustic environment. Use the table above for quick reference or the formula for detailed room analysis.

Interactive Charts

References

• Original Source