Doppler Effect: Finding Frequency vs Time

[nobb]

Hi.
I am doing a project about the Doppler Effect and I was wondering if someone here could help me. I have a tone source and I need to find the frequency with respect to time. I could use my mp3 player to record this frequency, which will then save it as a .wav file. I was wondering if there was software (free?) that could let me physically view the sound. I have already tried messing around with Nero's Wave Editor, but I am unable to get any relevant information from it. I would like to make a graph of frequency vs time. Any help would be appreciated. Thanks in advance.

 

[moose]

http://polly.phys.msu.su/~zeld/oscill.html

EDIT: However this does not graph frequency vs time or anything... i don't think

 

[chroot]

There are many freeware sound-editing tools that can tell you the frequency of your recorded sound. What you're looking for is sometimes called a 'sonogram.'

Sounds are not (usually) composed of a single frequency; they are composed of a number of different frequencies added together. A sonogram is a graph which shows the energy of the sound, in each frequency, versus time. Normally, time is the horizontal axis, frequency is the vertical axis, and the energy is represented by a color code (black meaning no power, bright yellow meaning lots of power).

You can probably find a bunch of programs on tucows.com. Here's one I found with a brief search:

http://www.avsmedia.com/AudioEditor/index.aspx

- Warren

 

[FredGarvin]

You could try something like this:
http://www.hitsquad.com/smm/programs/PocketRTA/

However, the best thing would be to find an app. that would produce a waterfall plot for you. It would be a frequency vs. amplitude vs. time plot. We use them all the time for vibration analysis and they are extremely helpful.

 

[hypermorphism]

Adobe Audition has a spectral view that shows an editable frequencyXamplitudeXtime graph of almost any audio format. You can download the full-featured tryout version here.

 

[dimensionless]

This might take signifgantly more effort, but it could be done in Matlab, or one of the free clones such as Octave or Scilab.

 

[robphy]

http://www.hitsquad.com/smm/win95/SPECTRUM_ANALYZERS/ and http://www.dxzone.com/catalog/Software/Spectrum_analyzers/ and http://www.epanorama.net/links/pc_sound.html point to some freeware spectrum analyzers for Windows. I think the one named by moose can also analyze the spectrum.

One feature that might be useful for your project is to convert the measured frequency into a speed, with knowledge of the natural frequency of the source. I'm not sure if any of the above software can output the measured frequencies to an external program or filestream.

If you have some programming skills and some time, you might write your own [with help from, say, http://www.relisoft.com/freeware/freq.html
http://www.delphiforfun.org/Programs/oscilloscope.htm
http://heliso.tripod.com/programm/sound/sound.htm or
http://www.hacker-technology.com/4361/30004.html ].

 

[nobb]

Thanks for everyones help so far. I have found what I am looking for and I am pretty sure it'll work. I already know the natural frequency of the source and I am just trying to find the changing frequency.

 

[xcorpionxting]

I'm still looking for a solution for the same problem (finding frequency). Can you please specify which solution did it for you? Thanks.