Variables | Definition | Unit |
p | Sound pressure at a given point at a given time | Pa |
| The maximum sound pressure of the sound wave | Pa |
| Angular frequency of the sound wave | s−1 |
| Speed of sound in a given medium | m∙s−1 |
u | Change in velocity of the medium due to sound at a given time | m∙s−1 |
| Maximum change in velocity of the medium due to the sound wave | m∙s−1 |
| Density of the medium under steady condition | kg∙m−3 |
k | Wave number | m−1 |
Ω | Energy flux density in direction of the sound wave | W∙m−2 |
I | Sound intensity | W∙m−2 |
T | The period of the sound wave | s |
| Characteristic impedance of sound of a certain material | kg∙m−2∙s−1 |
| Sound pressure due to the incident, reflected, or transmitted wave | Pa |
| Sound pressure due to the incident, reflected, or transmitted wave | W∙m−2 |
| Angle of incidence, reflection, or refraction | Radians |
| Coefficient of reflection of sound pressure, velocity, or intensity | No unit |
| Coefficient of transmission of sound pressure, velocity, or intensity | No unit |