# Air Presure and Air Velocity from speaker

How do I determine/calculate the air pressure emitted from a speaker ? And how to determine the velocity of air from the sound air pressure ?

$$v = \frac{P}{Z}$$
where $Z$ is the acoustic impedance. The linked article includes a table of values for the acoustic impedance of air. For air at sea level and room temperature the acoustic impedance is about 415 Pa s/m.