Doppler Effect Calculator — f′ = fv/(v − vₛ)
A source moving toward you squeezes the wavefronts together, raising the observed pitch. The speed of sound v = 343 m/s (20 °C air) is built in.
Doppler Effect Calculator — f′ = fv/(v − vₛ)
How to interpret the result
An ambulance siren at 700 Hz approaching at 30 m/s sounds like ~767 Hz to you — then drops below 700 Hz as it passes.
Assumptions
- Source moving toward a stationary observer
- Source speed below the speed of sound (no shock wave)
- v = 343 m/s