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Suggestions on how to find frequency of splashes (swimmer) in water using audio

Started by forthefunlulz July 11, 2008
Hi,

I am new to DSP and such, and I was wondering if you guys/gals can
give me any suggestions on hardware and software tools which can allow
me to plot the frequency of splashes made by paddling of the limbs.

Say we have a swimmer in a small pool. I want to know if I can find
out the frequency of the 'splashes' (I was thinking of using the sound
of the limbs moving and splashing in water as a count trigger) he/she
makes during a swim, using DSP and microphones. This experiment is to
see how fast he/she becomes tired.

I am thinking of doing this in small scale with bathtub toys which do
swimming animations first.

Has anyone got to do something like this? I was hoping for suggestions
in both hardware and software, as I am not familiar with DSPs.
Anything for doing the experiment for small tub toys.

Labview and NI compatible products would be good, but anything you are
familiar with is good for me too.

Thank you for any help.
Hi!

I would try to measure signal autocorrelation first. Just record the splashes for some time period (so you have 10-20 splashes), and calculate the autocorrelation values of this signal for different offsets.

Look at the autocorrelation function to see if that gives you a sensible information (peak at the delta T between splashes?). If yes, you can try further to extract dT automatically.

Cheers!
Catun

Hi,
>
>I am new to DSP and such, and I was wondering if you guys/gals can
>give me any suggestions on hardware and software tools which can allow
>me to plot the frequency of splashes made by paddling of the limbs.
>
>Say we have a swimmer in a small pool. I want to know if I can find
>out the frequency of the 'splashes' (I was thinking of using the sound
>of the limbs moving and splashing in water as a count trigger) he/she
>makes during a swim, using DSP and microphones. This experiment is to
>see how fast he/she becomes tired.
>
>I am thinking of doing this in small scale with bathtub toys which do
>swimming animations first.
>
>Has anyone got to do something like this? I was hoping for suggestions
>in both hardware and software, as I am not familiar with DSPs.
>Anything for doing the experiment for small tub toys.
>
>Labview and NI compatible products would be good, but anything you are
>familiar with is good for me too.
>
>Thank you for any help.
>
>