Dear Audacity forum,
We are studying African malaria mosquitoes’ flight behavior. We tether them inside a flight tube and record their flight for 10 hours using voice recorders (44100 or 8000 Hz, mono).
This results with large files which we need to extract the amount of flight from (the mosquitoes only fly for short periods of time, if any). Mosquito flight sound is generally between 500-2000 Hz.
I was wondering if there was any way to extract only the flight sound from these files, by either telling audacity what to look for, or better yet have Audacity export a data file and use R to extract the flight data somehow…
Any ideas on how I could do this?
We use Windows 7, Audacity 2.1.0 installed from zip file.
Love Audacity,
If you do use Sound Finder, I would suggest that you don’t run it on more than about an hour at a time. Nyquist plug-ins (Sound Finder is a Nyquist Plug-in) often have trouble with very long selections.
Thanks Steve for your prompt reply!
Can Audacity export the sound result after Equalization as a csv file for analysis elsewhere?
I have no difficulty in ‘seeing’ flight, I want to have it automatically extracted from the 10 hr file.
It’s actually more complicated since the flight sound varies in frequency as well, so I kind of answered my self here…
Again if there is enough amplitude difference between flight/non-flight you “may” be able to use Truncate Silence to remove the non-flight sections and so make a track that only contains flight sounds.
Thanks Trebor.
I actually know the work and the people - both wonderful!
Hoy et al were working with a different species than ours so I guess I should have specified we are working on Anopheles (not Aedes), which have a different fundamental frequency.
Right now I am interested in extracting active flight which generates the higher frequencies usually. Once I know how to isolate the ‘amount’ of flight from the track I can start playing with the range I guess
Thanks Gale!
The Sound finder does a pretty good job at detecting the flight and can be suitably adjusted for it.
Now how did you say I could extract the (label) data again?
So is the end objective a separate audio file for each instance of flight?
If so, you can use the region labels created by Sound Finder to export multiple, giving you one audio file for each labelled region.
The labels do not contain text data about the sample amplitude values. Is that what you want in the CSV file? If so, see Analyze > Sample Data Export….
Hi Gale, group!
First - thanks for all the replies and ideas. This is very helpful!
My goal is to learn how much flight took place in the 10 h trial/track, and when.
So I would like to be able to extract the flight periods from the background so I (A) can sum up the total duration, and (B) find out when the flight took place within the track.
Right now I am able to extract most of the flight but when I truncate the ‘silence’ (=background) I am left with a chunk of flight which only gives me the total flight, but not the times it occurred on.
Hi Themickster-
Thanks. No i have not tried these two options.
Can you please elaborate a little to the layman what these two options will do and how to use them?
Thanks
Sound Finder made region labels where the flight occurred. You can use File > Export Labels… which gives you a single text file listing the start and end point of each label (in seconds from the start of the track).
