Sound - Room Absorption Characteristics
The table below indicates mean sound absorption coefficient - αm - and reverberation time - Ta - for some typical rooms.
| Room Characteristics | Very Soft | Soft | Normal | Hard | Very Hard |
|---|---|---|---|---|---|
| Reverberation time - Ta - |
0.2 < Ta < 0.25 | 0.4 < Ta < 0.5 | 0.9 < Ta < 1.1 | 1.8 < Ta < 2.2 | 2.5 < Ta < 4.5 |
| Typical Room | Radio and TV studio | Restaurant Theater Lecture hall |
Office Library Flat |
Hospital Church |
Large church Factory |
| Mean sound absorption coefficient - αm - |
0.40 | 0.25 | 0.15 | 0.10 | 0.05 |
The mean sound absorption coefficient should be calculated when more accurate values are needed.
The diagram below can be used to determine the sound absorption in rooms of different sizes and with different accoustic characteristics.
Related Topics
• Acoustics
Room acoustics and acoustic properties, decibel A, B and C, Noise Rating (NR) curves, sound transmission, sound pressure, sound intensity and sound attenuation.
• Noise and Attenuation
Noise is usually defined as unwanted sound - noise, noise generation, silencers and attenuation in HVAC systems.
Related Documents
Propagation of Sound Indoors - the Room Constant
In a room the sound or noise will reach the receiver as direct and reverberant sound.
Sound - Reverberation Time
The sound reverberation time indicates how long it takes until the sound pressure level in a room is decreased with 60 dB.
Sound - Room Absorption Coefficients
Room sound absorption and absorption coefficients for common materials like plaster walls, brickwork, plywood panels and more.
Sound - Room Attenuation in Direct Sound Fields
Room size, absorption characteristics - and attenuation in direct sound fields.