Quiet-List 1997

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Re: Measuring noise



David,


> >Moderate rainfall (which might wake you up if you're a light sleeper) is 50
> >dB(A) and normal conversation is 60 dB(A). 
> 
>    These numbers seem kind of high to me.  My reference source (1981 
> Encyclopedia Britannica article "Acoustical Engineering") rates "quiet 
> conversation" at 30 dB, "ordinary conversation" at 40 dB and "noisy 
> office, telephone conversation, ordinary traffic" at 60-70 dB.

Ordinary conversation is between 50 dBA and 65 dBA, never 30 dB. Maybe the
EB is referring to the ambient noise level required to carry an ordinary
conversation. That would certainly make more sense.

>    It appears there is a difference of about 20 dB between our numbers.
> What reference are you using?  I realize your numbers are based on the 
> dB(A) weighting system, but I don't think there's that much of a 
> difference between the two systems (dB vs dBA).

You are right. Moreover, dB figures are higher than dBA ones, because
the dBA scale removes very low-pitched and very high-pitched sounds. So
ther is no explanation for that difference. EB is usually a serious
reference, but it must be a mistake in this case.

Regards.

Federico Miyara

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