Understanding the Effects of Doppler Shift on Sound Perception

Click For Summary

Homework Help Overview

The discussion revolves around the effects of Doppler shift on sound perception, particularly in the context of a train approaching an observer on railroad tracks. Participants explore how changes in the train's velocity affect the perceived loudness and pitch of the sound emitted by the train's whistle.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between the train's velocity and the perceived frequency of the sound, questioning how the changes in speed influence the pitch and loudness. There are inquiries about whether the pitch perception changes as the train slows down while still approaching.

Discussion Status

The discussion is active with various interpretations being explored regarding the Doppler effect. Some participants agree on aspects of the perceived frequency changes, while others raise questions about the implications of the train's deceleration on sound perception.

Contextual Notes

There is an underlying assumption about the constancy of the train's initial speed and the effects of its deceleration on sound waves. Participants are navigating the complexities of how these factors influence auditory perception without reaching a definitive conclusion.

jan2905
Messages
41
Reaction score
0
You are standing on railroad tracks as a train approaches at a constant velocity. Suddenly the engineer sees you, applies the brakes, and sounds the whistle. What do you hear starting at that moment?

Because the waves are "stretching" as it approaches you slower and slower, I said that the "loudness increases, and pitch decreases." Is this correct?
 
Physics news on Phys.org
Sounds good to me. As the train approaches you at slower and slower speeds, the apparent frequency of the sound would decrease.
 
But doesn't the fact that it's still approaching you make the pitch seem like its increasing regardless of acceleration?
 
The fact that there is velocity increases the frequency over what it is on the engine, ... but the gradient of velocity is decreasing the amount at which the frequency has been increased - i.e decreasing.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K