Ahmarra is a specialist manufacturer of bespoke internal acoustic doors for all sectors. We offer expert advice on the specification of acoustic doors ensuring that other requirements such as fire and accessibility can also be met.
Acoustics doors and decibel levels
Acoustic doors are produced in order to prevent noise escaping from a room, or to prevent noise from getting in to the room. An acoustic door won’t stop noise completely, but the door has been designed to withstand a certain specific level of decibel and will block much of the required noise. This is particularly important within a whole host of industries, including education, healthcare, industrial settings, music production and much more.
Noise reduction in acoustic doors is measured in RwdB
Rw – The ‘Weighted Sound Reduction Index’ is used to measure noise reduction. This expresses the difference between the sound intensity hitting one side of a structure and the resulting sound measured on the other side.
dB – The unit of measurement for sound is the Decibel. The Decibel (dB), is a logarithmic unit expressing the ratio between power and intensity. The intensity of sound follows an inverse square law from its source. For example, if you double the distance from a source of sound the intensity will be reduced by a factor of four. A sound 10 times more powerful than near total silence (0 dB) will be recorded at 10 dB, but a sound 100 times more powerful than near silence will be recorded at 20 dB.
Noise levels in education spaces
The table below shows the minimum permissable performance standards for airborne sound insulation between circulation spaces and other spaces used by students, for separating walls that do not have a ventilator. Values for refurbishment are also the minimum acceptable standards for alternative performance standards in new buildings.
| Workspace | New Build | Refurbishment | Acoustic Doorset |
| Secondary school music room
Control room – for recording Drama room Multi-purpose hall Teaching space intended specifically for use by students with hearing or communication needs |
45 RwdB |
40 RwdB |
35 RwdB |
| Primary music classroom
All other rooms used for teaching or learning |
40 RwdB |
35 RwdB |
30 RwdB |
The Department for Education’s ‘Acoustic Design of Schools Performance Standards – Building Bulletin 93’ offers full guidance on education acoustic standard – click here to view it.
Noise levels in every day life
It is important to have an idea of the different levels of dB in everyday life and how they compare.
- Near total silence is recorded at 0 dB
- A whisper from a few metres away is 15 dB
- A conversation at normal volume is recorded at 60 dB
- A car horn at 110 dB
- A jet engine at 120 dB
Your hearing tissue will be permanently damaged at 180 dB and partial hearing loss can begin at anything from 85 dB and above.
It is highly recommended that if you are subjected to over 100 dB that you should be protected if it is for longer than 15 minutes and at no point should you expose yourself to a decibel level of over 110 dB without any protection at all.
Here are some sound reduction guidelines:
| 20 dB | Normal speech will be readily audible |
| 25 dB | Loud speech will be clearly audible |
| 30 dB | Loud speech will be clearly audible under normal circumstances |
| 35 dB | Loud speech will be audible but difficult to distinguish |
| 40 dB | Loud speech will be faintly audible but cannot be distinguished |
| 45 dB | Shouting will be audible but cannot be distinguished |
| 50 dB | Shouting will be barely audible |
| 55 dB | Shouting will not be audible |
Please contact Ahmarra for more specialist advice on supplying acoustic doorsets for your project.