Dickcissel Night Flights | Home
Dick is software created by Old Bird, Inc. that is designed for detecting flight calls of the Dickcissel. To operate, locate Dick in a convenient place on your computer (e.g., in the C:\My Recordings folder). Create a folder called "temp" on the C drive and within the "temp" folder create a folder called "calls" [ C:\temp\calls]. Then, create a text file named "stop.txt" on the C drive [C:\stop.txt]. No text need be included in the file. The file name serves as the start and stop button for the software. To start the detection software, change the name of the "stop.txt" file to "go.txt" [C:\go.txt], then double click on the appropriate Dick icon to begin the program.
There are three versions of Dick. They are exactly the same except in where they receive inputted sound and how their detected files are named. To download, click on the appropriate link below (each ~760 kb download):
Dick-o is a version that is used for detecting night flight calls from VCR or other audio recordings. You start the program at the same time you start your audio recording playing into the computer. Detections are copied to wav files in the C:\temp\calls folder and given a file name that contains the word Dick and then the time of the detection. This time is the time elapsed from when you started the program Dick-o to when the detection occurred.
Dick-r is a version that is used for detecting flight calls directly from an active microphone. Detections are copied to wav files in the C:\temp\calls folder and given a file name that contains the word Dick and then the time on your computer when the detection occurred. If your computer clock is set accurately, then this time will be the time when the call occurred during the night. The date is also included in the file name. Dick-r is typically used in conjunction with the Windows Task Scheduler for automated nightly call detection (see discussion at end of computer section on the Recording gear page).
Dick-x is a version that is used for detecting calls directly from a wav file on your computer. To use this version you need to create a folder called My Recordings on your computer's C drive [C:\My Recordings]. Change the name of the wav file that you want to process for calls to Soundfile.wav [C:\My Recordings\Soundfile.wav]. Then, as with the other detectors, change C:\stop.txt to C:\go.txt and double click on the Dick-x icon. Detections will show up in the C:\temp\calls folder. Processing takes place faster than real time, typically a half hour or so for an 8 hour sound file on a computer with a 1 GHz or faster processor. File names contain the word Dick and the time of the detection. This time is the time elapsed from when you started the program Dick-x to when the detection occurred. Note: this software only works on mono, 22050 sampling rate, 16 bit, wav files.
General Information on all Dick detectors
All the Dick detectors produce a text file in the C:\temp\calls folder with a logarithmic index to variation in hourly sound energy for the 4.0-5.5 kHz frequency band. The file name is LogDick.txt.
All the Dick detectors have an automatic shutdown mode that is triggered when 25 or more detections occur within 20 seconds. This, to some degree, prevents massive numbers of false detections due to rain drops, continuous song from insects and frogs, or mechanical noises. The detection operation resumes again as soon as the program sees that detections fall below 25 in 20 seconds.
How it works
The software is comprised of two processes. These operations capitalize on unique characteristics of the Dickcissel flight call to distinguish it from other transient sounds in the night: first, that a large portion of the energy of the Dickcissel flight call is in the 4.0-5.5 kHz frequency range, and second, that such calls typically consist of a series of up to 12 short notes equally spaced about 16 msec apart (see spectrogram). The first part of the software is an acoustic transient detector (ATD) that analyzes a single audio stream looking for the beginning and end of a burst of acoustic energy. The ATD thresholds the slope of the smoothed log-magnitude signal energy within the 4.0-5.5kHz frequency band. A large positive slope triggers the beginning of a transient; a large negative slope marks the end of a transient. The second part of the software computes a smoothed energy envelope of the audio signal and looks for a concentration of the Fourier spectrum of the envelope in a specific narrow frequency band. When both parts of the detection software are triggered, a detection is logged and the sound is copied to a file on the hard drive.