I have tried to simulate the doppler effect on scratch. To use this project, click "see inside" and set the "Emitter Speed" to whatever speed you want the the moving object to be traveling at(<= 34 because 34.3 represents 343 m/s, the speed of sound), and the "Base" to whatever frequency of sound the moving object is emitting from its own frame of reference. After doing this, click play to simulate the doppler shift.
Cool tip: If you set the speed above 34.3, the doppler audio will be messed up(the shift trends to infinity), but you will hear a sonic boom as it passes over you. Note: Sorry if the audio is a little bit choppy.
