Science Buddies: "Ask an Expert"

My science project is about whether the gender of a cat effects the volume and pitch of it's purr. I'm recording the purrs of different cats around the neighborhood, and that is going fine, but I'm having more trouble with finding the measurements of the volume and pitch. I converted the recordings into wave files on my computer, but though I've tried a lot of different computer programs, all of them were either too complicated, or didn't tell me what I was looking for. Eventually I got a freeware called Spectro that seems to give me results, but the numbers don't make sense. I says that one of my recordings is -100 dB. Is that even possible? Does this data make sense and I'm just interperting it wrong, or is the program just a fake? I have some wave files and some screen prints of what those files look like on the computer program. I can't figure out how to send an attachment, but if it would make it easier for you, I can try to find a way to send those to you.
Thank you.

One thing to think about would be what uncontrolled variables there might be in your test that might be correlated with gender. For example, weight and size of cat.

Regarding the analysis of the files, the freeware audio editing/analysis tool I usually use is Audacity. It can be found here: http://audacity.sourceforge.net/

Hello and welcome to the forums!

As you found, there are a number of computer programs available to tell you the pitch and volume level of your data. I personally use Audacity, but there are many options.

When it comes to measuring volume, you may have several difficulties. First, how can you control for the distance of the microphone from the cat? Sound pressure (volume) will drop quickly with distance, so this parameter must be controlled very carefully.

The -100 dB number probably does indicate an error. It would be great if you could post some of your data. To post files, follow this information: https://www.sciencebuddies.org/science- ... 642603cba4

Keith

Thank you all for your suggestions. I just downloaded Audacity, and it seems to be working really well, though I have to familiarize myself with the program a little bit more. Thank you also for showing me how to do attatchments, but I can't send my wave files or screen prints to you because they have too many kg.

I'm having the same problems...all of the software programs that I found don't seem to be giving me what I want. I think I will try Audacity, though. Maybe it will work.