[A/S] Sound Levels (Was: Generators - 2 vs 1)

[Tuna <rctowns@xxxxxxxxxx>]

It's been a while since my membership in the Audio Engineering Society
lapsed, but i have a feeling that we're talking about two kinds of decibels:
dBm and dB(A). In an electronic amplifier circuit, a doubling of amplifier
power (in watts) is required to produce a 3 dB (in millivolts) increase.
However, in acoustical terms, a 3 dB increase can be thought of as a JND
(just noticeable difference) in subjective terms... The reference usually
used is 'conversational level' being at about 72 dB at close range (3 ft?).
'Pain level' is somewhere up around 110 - 120 dB, as i recall. The ratings
given to these generators are in acoustical dB, usually at 3 meters or 10
feet, so my reference to conversational level and generators rated at 73 dB
at 10' was not quite accurate. Bottom line: a 3 dB(A) difference is a
'noticeable difference', not necessarily 'twice as loud'...

Also, acoustical dB references are highly subjective, when applied in the
real world. 72 dB of generator sound in the dead of night in a national park
might be highly objectionable, but completely acceptable in a WalMart
parking lot near the freeway in Omaha... Likewise, 72 dB of Julia Roberts at
a distance of 3 feet might be highly preferred over 72 dB of Fran Drescher
at 10 feet... (c;

Tuna
'48 Trailwind
WBCCI#8862/VAC
Reno, NV