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Speakers and dB
Name: Scott S.
Status: Student
Age: 30s
Location: N/A
Country: N/A
Date: 2001
Question:
If I have 3 sound sources located adjacent to each other
each with a maximum signal level of 65 dBA, is the cumulative sound
level
additive?
Do I end up with a cumulative sound pressure level of 195 dBA
near these sources?
Replies:
Hi, Scott !!
The sound pressure in this case is NOT cumulative.
To be cumulative, the air of a sound box should receive
the energy of the second sound box after the first one,
and the same for the third. Surely there will be an interference
between the pressure waves that tends to cumulate the
pressure, but NOT in a linear fashion due to several factors
like air viscosity, open or closed room, temperature of the
air, etc.
A person talking measures about 50 decibels (dB). A
vacuum cleaner measures 70 dB, etc. 10 people talking
are NOT ten times louder than only one talking, although
the way our ears and brain pick up the sound may indicate
the contrary.
Regards
Vince Calder
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Update: June 2012
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