## Sound Pressure Level Formula :

Sound pressure level denoted L_{P is equal to the }20 log_{10 }and multiply the root square sound pressure P_{rms(Pa) } in pa divided by reference sound pressure in P_{ ref(pa)} in pa.

**L _{P}=20 log_{10} ( P_{rms(Pa) /} P_{ ref(pa)} )**

Where,

L_{P→ denoted in dB}

P_{rms }→ root mean square sound pressure in pa,

P_{ ref} →reference sound pressure in pa(20 μ p_{a})

μ → permeability in Wb/A.m

## Sample Sums :

### Sum 1 :

Calculate the sound pressure level if the rms pressure value is given as 50 μ p_{a}

### Solution :

Given,

P_{rms}=50 μ p_{a}

P_{ ref=}20 μ p_{a}

The sound pressure level formula is given by

L_{P}=20 log_{10} ( P_{rms /} P_{ ref} )

L_{P}=20 log_{10}(50/20)

L_{P =}7.95 dB

### Sum 2:

Calculate the sound pressure level if the rms pressure value is given as 90 μ p_{a}

### Solution :

Given,

P_{rms}=80 μ p_{a}

P_{ ref=}20 μ p_{a}

The sound pressure level formula is given by

L_{P}=20 log_{10} ( P_{rms /} P_{ ref} )

L_{P}=20 log_{10}(80/20)

L_{P =} 1.2041dB