Ahmarra is a specialist manufacturer of bespoke 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 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.

Workspace Recommended performance standard for doorsets (dB)
Offices 40 – 45 dB
Large Offices 45 – 50 dB
Classrooms 30 dB
Large Lecture Rooms 35 dB
Music Room 35 dB

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.