Which of these is the effect on the frequency of sound waves caused by the movement of their source?

Thank you Sheldon! I even remember the costume lol

Anup Toms Alex, it’s not the loudness that’s changing. It’s the frequency that’s changing. you hear a higher pitch when it’s approaching and a lower pitch when it’s going away. the reason for the confusion is that the human ear is more sensitive to the higher frequency than the lower frequency so you actually think the volume is going down, but it’s not.

I kept wondering about police sirens and whether or not the siren actually rises and falls, or if it's a flat tone whose rise and fall is due only to the Doppler effect. Feeling that I needed an answer, I called the non-emergency number at my police department and asked the officer who was lucky enough to take my call, and I now know that it's all Doppler effect.

We learned this in high school science on the front oval.

Thank you big bang theory , I agree with Nanna

I had no idea that phenomenon had a name! Very interesting.