From the spherical wave attenuation formula Lp=Lw-K+DIm-Ae
Lp=Lw-K+DIm-Ae
(1) radiation is a spherical wave, and the divergence attenuation k:
K= 10log( 10，4π)+20log( 10，r)
Where r is the distance between a and b.
(2) Directivity factor DIm: Whether there is a reflecting surface near the sound source (the ground is considered separately), or whether the sound source itself is not a point sound source. Adding a reflecting surface will increase 3dB.
(3) Other additional attenuation Ae
Air absorption: Aa (related to frequency, pressure, temperature and humidity)
At 20℃: AAO = 7.4× 10 (-8) F 2 r/H DB.
aa(t)=aao/[ 1+4× 10^(-6)△t f]
Where h: relative humidity of air;
F: sound frequency.
Additional attenuation of obstacles: Abhp (the universal lookup table)
Empirical formula: AF = 0.0 1dF (1/3)
Meteorological additional attenuation amplitude modulation
Mainly wind speed and temperature gradient, the specific impact can be obtained by looking up the table.
In this example, only the influence of k is considered.
Get LP = lw-k.
Xiaoming heard that 130dB.
The relationship between sound intensity and anger will be discussed below. First, the level of anger should be defined.
Binary discrete distribution model
Suppose that an individual may make two behaviors: angry behavior q+ and angry behavior q-, and
F(Q+)=G ( 1. 1)
Then there is
F(Q-)= 1-G ( 1.2)
G can be used to measure anger.
When I take the medicine, I will talk nonsense again.