Audio Engineering

Measurement 53

This integration reduces to

LEQ

10

10 3 6

3600

(^9010)
log
.s
s

.

⎛

⎝

⎜⎜

⎜⎜⎜

⎞

⎠

⎟⎟

⎟⎟

⎟

Thus 1.0 hour of noise energy at 60 dBA is the equivalent energy exposure of 90 d B A
for 3.6 s.

170

160

150

140

130

120

110

100

90

80

70

60

50

40

30

100,000

10,000

1000

100

10

1

0.1

0.01

0.001

0.0001

0.000 01

0.000 001

0.000 000 1

0.000 000 01

0.000 000 001

Power

(watts)

Power Level

dB re: 10−^12 W Source

20 to 40 million195 Saturn rocket

Ram jet

Turbojet engine with afterburner

Turbojet engine (7000 lb thrust)

4 propeller airliner

75-piece orchestra

Pipe organ

Small aircraft engine

Large chipping hammer

Piano

BBb tuba

Blaring radio

Centrifugal ventilating fan (13,000 CFM)

4-ft loom

Auto on highway

Vane axial ventilating fan (1500 CFM)

Voice—shouting (average long term rms)

Voice—conversational level

(average long-time rms)

Voice—very soft wisper

Peak rms values

in 1/8 s intervals

Peak rms values

in 1/8 s intervals

}

}

Figure 2.7 : Typical power and LW values for various acoustic sources.