The particle velocity level or the sound velocity level tells the ratio of a sound incidence in comparison to a reference level of 0 dB in a medium, mostly air.

It shows the ratio of the particle velocity v₁ and the particle velocity v₀.

The particle velocity level is:

where v₁ and v₀ are the velocities.

The particle velocity level has the letter "L_v".

The unit of the particle velocity level is named "dB".

Notice: The dB is dimensionless.

If v₀ is the standard reference particle velocity of:

we use "dB SVL". (SVL = sound velocity level).

Sound particle velocity v should not be confused with Sound velocity c.