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Starting the automated sound processing for the first time



When you click the ‘start’ button, SA+ will start monitoring the input addresses to detect new sound files. Then, SA+ processes each sound file separately. It first performs spectral analysis and feature calculation, segmentation and computation of syllable features. Based on those measures it ‘decides’ if to save or discard the data. A decision to save means that 1) the sound file will be moved to a permanent storage address, 2) the raw feature file will be created and saved in a permanent storage address, and 3) the detected syllable features will be saved by adding records to the syllable-table of this animal.  

Vocalization or noise? The Sound Analysis Recorder already eliminated all the ‘empty’ sound streams from the recording channel based on simple amplitude filtering. We now need to make an accurate determination for each time window, if it contains animal vocalization or not. SA+ uses several criteria to make this determination, and here we only discuss (in a nutshell) the two central controls, which are amplitude and Wiener entropy thresholds. The yellow slider at the left of each spectral display is for controlling amplitude threshold, whereas the red slider is for controlling the Wiener entropy threshold. In other modules of SA+ you can change these controls ‘live’ while SA+ interactively updates the display and the calculation of features. However, this ‘live; feature is implemented in the ‘live’ mode, since in this mode, SA+ keeps bouncing from processing one sound to the other. This means that whatever change you have made to the sliders, you will only see its outcome the next time this channel processes a sound file. We therefore recommend that you first make yourself familiar with how these sliders work in the ‘Explore & Score’ module. 

Setting the amplitude threshold:

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