Investigating the Doppler Effect on Conversation Outcomes

In summary, the conversation discusses the experience of one person who was talking to a friend near a main road when a loud vehicle passed by. The person could not hear their friend during the passing of the vehicle and wanted to know why. The experts in the conversation explain that this is due to the masking effect of "white noise" from the vehicle, which drowns out other sounds and makes it difficult to differentiate between them. They also mention the concept of contrast or signal to noise ratio, where the loudness of the vehicle's noise overpowers the sound of the person's voice. The experts provide resources for further understanding of the topic and encourage the person to develop a deeper understanding of physics instead of just memorizing information.
  • #1
I noticed that once I was talking to a friend close to me and then a vehicle passed by with a huge sound and then I merely heard what he said.

Can someone explain me why ? even though that friend was close to me ?

Does it have any connection with the Doppler effect ?
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  • #2
You probably were surrounded by "white noise" while that speeding car passed by. The noise it generates has a masking effect and drowns out conversations, so it's no surprise you barely heard what your friend said. Although there is a doppler effect when a moving sound source passes you, it does not account for what you have asked about. For a great article on the sound a passing car generates see:[/URL]

Be sure to use google and wikipedia to find answers to your questions...they are your friends.
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  • #3
He said "merely" not "barely". As it is the question is ambiguous. The way it's phrased now implies that all he heard was his friend speaking and he did not hear the truck at all.
  • #4
Dr Morbius, of course you are correct. I did assume the OP's meaning. Jadaav needs to rewrite his question in correct and clear English.
  • #5
Bobbywhy said:
Dr Morbius, of course you are correct. I did assume the OP's meaning. Jadaav needs to rewrite his question in correct and clear English.

Right, then I rewrite. Thought it was clear what I first wrote but never mind.

The other day I was talking to a friend who was near me at about not more than 2m, along the main road. Some time later, a lorry passed by and I couldn't hear what he said during that particular moment. I could only see his lips moving.

When the lorry went, then I could hear him again. I wanted to know how is it possible that I couldn't hear my friend talking but instead heard the sound of the lorry ? What happened to the sound wave which came from my friend ?

I hope, I'm clear this time.:smile:
  • #6
Bobbywhy said:[/URL]

Be sure to use google and wikipedia to find answers to your questions...they are your friends.[/QUOTE]

The website says Page cannot be found.

And yeah, I always use google and wikipedia. They're definitely the best friends that you can have in the internet.

I just didn't know what to search for on this.
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  • #7
you said: 'a vehicle passed by with a huge sound'

The 'huge' sound from the vehicle did nothing to your friend's sound. It cannot!
the amplitude induced at your eardrum by the vehicle's 'huge' sound was high; much more than your friend's sound. So even though both the sounds reached your eardrum, you simply could not differentiate between the two: your eardrums were already too stressed and could not afford to vibrate for your friend's sound simultaneously.

comments welcome.
  • #8
You couldn’t hear your friend when the lorry passed because his voice was masked by the loud (white) noise from the passing lorry. Once the lorry passed by you could hear him again. Try this website for a good explanation:[/URL]

Here is a sample paragraph from the above site:

Noise from tire-roadway interface and engine exhaust noise.

This category includes delivery vans, such as UPS and Federal Express trucks, large sport utility vehicles with knobby tires, large diesel engine trucks, some tow-trucks, city transit and school buses with under vehicle exhaust, moving vans (U-haul-type trucks), small to medium recreational motor homes and other larger trucks with the exhaust located under the vehicle. Typical noise levels for medium trucks are 80 to 82 dBA at 55 mph at 50 feet.
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  • #9
Also, consider what I like to call "contrast". (Or signal to noise ratio)
Before the vehicle, your friend's voice (the signal) is much higher than the background (the noise). When the truck passed by the background increased so high that the signal to noise ratio was much much lower than it was before. Similar to being able to clearly see something black on a white background compared to barely being able to see the same thing when it is a very very light gray instead.(Contrast!)

So, assuming the sound wave made it to your ear without being disrupted, and your ear still processed your friends voice, the difference between his voice and the truck was so small that you simply couldn't make it out.
  • #10
Right got it now.

So when the truck/lorry came near, its amplitude that is, its loudness increased. Thus it overcome the loudness of my friend's voice. My ear did process both sounds but I simply couldn't differentiate between them.

Is it right ?
  • #11
Jadaav: try to develop confidence; physics is not something to memorize.
  • #12
Yes, Jadaav, you've got it now!
  • #13
hellboy4444 said:
Jadaav: try to develop confidence; physics is not something to memorize.

That's the reason I like physics so much:D You just need to understand it:)

Thanks to all of you for helping me.

1. What is the Doppler Effect?

The Doppler Effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave.

2. How does the Doppler Effect affect conversation outcomes?

The Doppler Effect can affect conversation outcomes by altering the perceived pitch and volume of a speaker's voice. If the listener is moving towards the speaker, their voice will sound higher and louder, and if the listener is moving away, their voice will sound lower and quieter.

3. Can the Doppler Effect impact communication in loud environments?

Yes, in loud environments, the background noise can mask the subtle changes in pitch and volume caused by the Doppler Effect. This can make it more difficult for listeners to accurately perceive the speaker's intentions and emotions.

4. Is the Doppler Effect only applicable to sound waves?

No, the Doppler Effect can also occur with other types of waves, such as light waves. In this case, the color of the light may appear to shift towards the blue end of the spectrum if the source is moving towards the observer, and towards the red end if the source is moving away.

5. How can the Doppler Effect be controlled or minimized in communication?

The Doppler Effect can be controlled by keeping a consistent distance between the speaker and listener, or by standing still while speaking. In situations where movement may be unavoidable, using microphones and speakers can help to mitigate the effects of the Doppler Effect on communication.

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