Welcome Guest! The IOSH forums are a free resource to both members and non-members. Login or register to use them

Postings made by forum users are personal opinions. IOSH is not responsible for the content or accuracy of any of the information contained in forum postings. Please carefully consider any advice you receive.

Notification

Icon
Error
3dB(A) = doubling of noise?
Options
Go to last post Go to first unread
Previous Topic Next Topic
Admin  
#1 Posted : 20 July 2006 10:34:00(UTC)
Rank: Guest
Admin
Posted By Juliet Fennell Can anyone help? Im convinved that an increase of 3dB(A)is a doubling in noise while a colleague is convinced its 10dB(A) Anyone know the answer? Thanks, Juliet
Back to top
Admin  
#2 Posted : 20 July 2006 10:51:00(UTC)
Rank: Guest
Admin
Posted By Martyn Hendrie The Bell (or decibel scale) is logarithmic (i am going to make no attempt to explain logarithms) but the affect is that every increase of 10 decibels is an increase of 10 times the sound energy. Working backwards from that a 3dB increase doubles the sound energy.
Back to top
Admin  
#3 Posted : 20 July 2006 10:52:00(UTC)
Rank: Guest
Admin
Posted By Diane Thomason You are right, it's 3 (i.e. increase of 3dB(A) means that the sound pressure level is doubled.
Back to top
Admin  
#4 Posted : 20 July 2006 10:54:00(UTC)
Rank: Guest
Admin
Posted By Alan Hoskins Hi Juliet, An increase of 3 dBA is a doubling of sound pressure level. An increase of 10 dBA is required for a sound to be perceived as being twice as loud. Alan
Back to top
Admin  
#5 Posted : 20 July 2006 10:59:00(UTC)
Rank: Guest
Admin
Posted By Juliet Fennell Thanks guys. juliet
Back to top
Admin  
#6 Posted : 20 July 2006 11:40:00(UTC)
Rank: Guest
Admin
Posted By IT It is actually called the rules of 3 I.E 1 machine 85 dba 2 machine both emitting 85 dba is represented as 88 dba make your friend pay for the drinks
Back to top
Admin  
#7 Posted : 20 July 2006 12:38:00(UTC)
Rank: Guest
Admin
Posted By Charley Farley-Trelawney Juliet Alexander Graham Bell founded the concept of decibels and formulated a logarithmic range based on 10. "Deci" refers to the base 10 log scale, and "bel" refers to Alexander Bell. Each 10-dB increase represents a tenfold increase in sound intensity. In addition, a 10-dB increase is perceived as more or less doubling-up on loudness. I believe therefore, your friend may well be referring to this equation; as other responders have explained in detail I will not at the risk of becoming boring repeat any of those replies. Best wishes CFT
Back to top
Users browsing this topic
Guest
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Powered by YAF.NET | YAF.NET © 2003-2025, Yet Another Forum.NET