[OT] Decibels and the ear [was: Re: [plug] Hot and bothered CPU hankers for cool breeze]

[James Devenish]

In message <20031217012435.GA15677 at pinion.innovative.iinet.net.au>
on Wed, Dec 17, 2003 at 09:24:35AM +0800, Bernd Felsche wrote:
> If dbA is mentioned, then it's sound pressure level with respect to
> 20 micropascals at 1000Hz, the "least discernable" sound by the
> human ear.
[...]
> 256 machines would be 8 * 3 dBA, i.e. 24 dBA louder if equi-distant
> from the observer. 400 machines would be around 26 dBA louder.

Thanks.

In message <20031217012435.GA15677 at pinion.innovative.iinet.net.au>
on Wed, Dec 17, 2003 at 09:24:35AM +0800, Bernd Felsche wrote:
> On Tue, Dec 16, 2003 at 09:50:21PM +0800, James Devenish wrote:
> > I'm not sure that the 'semantics' of aural decibels are well defined
[...]
> They are well-defined. Hence A-weighting for low to medium sound

After doing a bit of Googling, it seems Cameron really meant what he
wrote for his initial comment that 10dB ~= twice as loud :-) So, a
nominal three decade increase from 399 extra machines could be perceived
as eight times louder than one machine, which is the sort of thing I was
wondering about. Sorry everyone!

In message <3FDFBD8E.6070406 at postnewspapers.com.au>
on Wed, Dec 17, 2003 at 10:21:02AM +0800, Craig Ringer wrote:
> I wear earplugs at work (as I'm in here with the servers),

Heh, I used to wear earplugs when I was in a very quiet office. Maybe
I should do the same where I am now, as I continually have nefarious
thoughts about disabling the machine that's next to mine.