Some facts about the Doppler effect

Hi in this post I will be talking about the Doppler effect that was discovered by an Austrian scientist named Christian Doppler.Doppler thoght that a moving sound always changes pitch in the same way which is the Doppler effect.When the sound waves comes towards a person they are squashed together.So one will hear the sound in quick succession at a high frequency.As the sound moves away one hears it at alower frequency because the sound waves are more widely spread.This was tested by a sccientist by putting a band of buglers to play on a moving train and have the train to drive past him.