Sitemap
Print
Home
Dansk
English

NOISE AND SOUNDS

Sound insulation, Vibration damping and Thermal insulation

 

What is noise?
 

In a publishing of a textbook in noise measurement, form the Danish noise measurement firm "Brüel og Kjær" there is a quite accurate quotation on the first page:

"Noise is an unavoidable part of life in our modern society. Technological progress has led to producing more and more noise from machinery, businesses, traffic, etc.
It is very important, that we make some effort in trying to change this, so that noise do not have to be necessary everywhere. But to do something about the noise requires a particularly knowhow about the origin of the noise, how it spreads, and how it is measured." 

       

A summary of the above statement explains quite clearly, what the products produced from B6 Akustik is all about!

Noise is not a thing that we need to accept – we can actually do something about it. The key to success is very simple – we need knowledge about noise and sound, as well as a good experience in what to do in each situation. 
 

 

Where is the limit for noise?
 

The word “noise” covers the concept of unpleasant or unwanted sounds. When a sound irritates your ears, it is not only about the sound, but also about our attitude to the sound.
 
If we are having a party or just in a good mood - loud music is a good experience, but the day after when the neighbours are making noises, the same music is suddenly an annoying noise, because our attitude towards it is different. 
 
If a sound is perceived as noise or not, is not only about how amplitude the sound is. A dripping tap or a scratch in a record can easily be more annoying than a thunderclap. Sound and noise are therefore two different things. A sound can so to speak be experienced as a pleasant ting, or as plain noise - depending on the context in which it is included.


 
 
 
 

       

It is quite individual who develops hearing damage, but an average evaluation is concluding the following:
 
(a) An 80 dB load in 10 years, average 8 hours a day, there is very little probability of getting a hearing damage. 
   
(b) An 82 dB load in 10 years, 1% to 2% will have a hearing damage – and this have nothing to do with age.  
  
(c) An 85 dB load in 10 years, approximately 4% will have a hearing damage, again which has nothing to do with age.  
 

(d) On a 90 dB load, approximately 11% will have a hearing damage, again which has nothing to do with age.
  
The risk of losing some hearing abilities is very possible. The risk of getting tinnitus combined with a hearing damage is maybe less. Nevertheless, this suffering can very easily be debilitating and have far reaching consequences for both work and private life.

 

What is sound?
 

Definition:
The word Acoustics is a branch of physics and the study of sound and waves in gases, liquids and solids.

The technical definition of sound:
Sound is a pressure of variations in, for example, air (or water). Pressure variation exerts through the air as sound waves and when they affect the eardrum in the human ear, it starts to vibrate. 
 
The vibrations will through the middle ear and in the inner ear - be transformed into nerve impulses that the brain perceives as sound. 
 
The ear can perceive a very big sound scale - from the sound of a tiny pin falling to the ground, up to the noise from a jet plane. 
 
The sound is perceived as deep or high, depending on how many times the pressure varies per minute. That is what we also call frequency and frequency is measured in Hertz. 
 
An average young person can hear frequencies between 20 Hz and 20,000 Hz.
 
Sound strength corresponds to sound pressure. Quite literally, the pressure the eardrum is exposed to when the sound hit the ear. 
 
To describe the sound strength we often use the decibel scale. 
 
The Decibel scale is from 0 dB, which is the limit for audible hearing, up to 140 dB, where the sound pressure becomes so strong that it becomes truly painful. 
 
The Decibel scale shall contain all of these sound pressure levels, and therefore it has been necessary to make a particular subdivision. 
 
When you go up or down in the scale, it is always a 3 dB doubling or halving of the sound.

       

This means that twice the 80 dB is not 160 dB, but 83 dB.


If you measure the level of a kindergarten, it is very important to know if the measurement was 80 or 83 dB. At the same time, reducing the load of 3 dB will have a very important effect for the working environment. 
   

 
 

What is a sound wave?:

A sound wave is defined by the speed, amplitude and frequency.
The sound speed depends strongly on the media through which it moves, but also by the temperature. Sound speed is approx. 340 m/s in air - and 1500 m/s in water.

The Wavelength is equal to the distance between two peaks of a wave. Sound wavelength, λ is related to the sound speed c and its frequency f by the formula:
  
  

λ = c/f
 
λ = wavelength of the sound,
c = speed of the sound
f = frequency of the sound 
 

 
Source:
Interpretation of texts and quotes by Brüel & Kjær: Grundbog in Sound-measuring, Uffe Jørgensen, 1987

 

DATA SHEETS

Se flere data om lydisolering, vibrationsdæmpning og termisk isolering

      
        

    ACOUSTIC PRODUCTS

Se flere og andre polymere løsninger..!

           
       

   OFFICE ACOUSTIC

          

         

SOUND BAFFLES

   
     

BROCHURES

Download vores brochure

                  

                 

CONTACT US

    

B6 Akustik A/S
Professional noise reduction & Technical applications in foam
B6 Akustik A/S - a part of B6 Gruppen
email(at)b6akustik.dk | www.b6akustik.dk | Tranåsvej 5-7, DK-9300 Sæby | Tel. (+45) 9989 1050 | Fax (+45) 9989 1060