The FlowFX noise.

[MuFu]

Guys, sorry to pull my audiophile knowledge out here, but the human ear percieves every 3 db as twice as loud.....

No, that's wrong. +3dB is double the electrical power. +6dB is double the voltage. It is generally accepted that twice the perceived volume corresponds to 7-10dB gain.

MuFu.

 

[martrox]

Jeez..... defining db is tough, like talking different languages. MuFu, please check this out:

http://www.howardleight.com/Industrial/education/Glossary.html

Exchange Rate
The rate in which sound energy is averaged over time. Utilizing a decibel scale, every time the sound energy doubles, the measured level increases by 3 dB. This is the 3 dB exchange rate that most of the world uses.In the U.S., OSHA uses the 5 dB exchange rate.

I'm sure we can argue this out, but I guess we need to define just what we are arguing about first!

 

[MuFu]

Exchange Rate
The rate in which sound energy is averaged over time. Utilizing a decibel scale, every time the sound energy doubles, the measured level increases by 3 dB. This is the 3 dB exchange rate that most of the world uses.In the U.S., OSHA uses the 5 dB exchange rate.

Sure, that's correct (although their definition of the decibel leaves a little to be desired...).

I am talking about perceived loudness and I thought you were too (use of the word "perceives" on your part was a big clue, hehe). There has never been any scientific derivation of equations relating sound intensity and perceived loudness, but all empirical testing points to a relationship involving a doubling of "perceived volume" every 7-10dB. Of course, it isn't that simple - human hearing is neither linear nor logarithmic in reponse. There are so many other factors - frequency, tone etc that affect the way in which we perceive sound levels. I am sure pychoacoustic engineers (pschoacousticians?!) spend years and years tryin to model hearing using factor x for ear size, ear shape y, hair colour z, mum's name n, favourite colour c etc etc.

Damn audiophiles...

MuFu.