Software 01db Tutorial II Creating and Analyzing Audio Files
Making Audio Recordings Using the O1dB Software Making real time audio recordings using the 01dB software is easy. If you are already running a real time measurement window just left click on the Start Audio Record button (See the figure below). When the button is pushed there will be a short delay. Then the computer will begin making the recording. When the audio recording is done an Audio file will show up in the CMG1 main window.
Start Audio Record Button The length of time of the audio recording can be adjusted by clicking on Config and then Audio in the DBFA32-real1 window. An Audio record parameters window will then appear (see below). Use the up and down arrows in the window to adjust the length of time of the audio recording.
Viewing Audio Recordings You can view an audio recording by going into the CMG1 Main window and double clicking on the audio file that you want to look at. A window like the one below will appear.
Use left mouse button to adjust cursers The command buttons above and to the left of the display window allow you to select and view different parts of the audio recording. Use the cursers and zoom command to view different parts of the time signal in detail. Analyzing Audio Files To analyze an audio file highlight it in the CMG1 main window and then go up to the dBFA32 CMG1 window and push the Computation Server Y/N button. This is the button with the green calculator on it. When you do this a widow like the one below will appear.
Click view analysis options
Push to execute an analysis
Stop button
When this window comes up click on the button with the screwdriver on it. This will open a window that lists all of the calculations you can perform on the audio file. The window will look similar to the figure below. The buttons and windows in this figure are described below.
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List of available processings - List of available processings: it shows all the types of processings compatible with the active script. The same operator can be used several times with different parameters to process the same items. Designation - Give a name to the script. A user-defined name can be specified. Set of active processings currently part of the script. These operators will be activated to analyze independently the same set of items when running the script.
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Edit - Edit the parameters of the selected operator (in the list of available processings). Each operator shows its own configuration dialog box. Comments - Comments describing the operator selected in the available processings' list. If an operator from the active processings' list is selected, the comment field shows the type of the operator. Add - Key >> that allows adding an operator into the active processings' list. Different operators of the same type may be added (the user may for example define a multispectrum analysis in third octave band with different time steps in the same script). A generic name for each operator is given by default. Remove - The list on the left tells you what kind of analysis options are available.
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Highlight the type of analysis that you want to perform in the list of available processings and then click on the >> arrow keys to move it over to the active processings box. If you highlight a function in the active processings box and then hit the Edit key you can edit the parameters of the of that particular processings request. A description of each of the available processings options and what they do is given below. Broad band spectrum - This analysis results in a broad band spectrum, ranging from to octaves 1/48th octaves, with time history capability (broad band multispectrum). The user may either use digital filtering (Class 0 IEC1260) or FFT synthesis. Narrow band spectrum - This analysis results in a narrow band spectrum, with time history capability (narrow band multispectrum) and frequency zoom. The user specifies the FFT window, the overlap and the number of lines. Undersampling - This analysis results in an undersampled time signal, fixed by the user. A low-pass filter (Butterworth order 20) ensures anti-aliasing, the undersampling ratio varies between 2 and 50. Low pass filtering - This analysis results in a low-pass filtered time signal (Butterworth, even order from 2 to 30). High pass filtering - This analysis results in a high-pass filtered time signal (Butterworth, even order from 2 to 30). Band pass filtering - This analysis results in a band-pass filtered time signal (Butterworth, even order from 2 to 30). Cut-band filtering - This analysis results in a band-cut filtered time signal (Butterworth, even order from 2 to 30). Notch filtering - This analysis results in a Notch filtered time signal. The user defines the filter selectivity (S factor). The frequency range at -3 dB is then of fe / (PI * S) for an order 2. By increasing the order number, Attenuation is emphasized at the expense of Selectivity.
A weighting - This analysis results in an A-weighted time signal. The filter used fulfills Type 0 requirements of standard IEC651 and equivalent. B weighting - This analysis results in a B-weighted time signal. The filter used fulfills Type 0 requirements of standard IEC651 and equivalent. C weighting - This analysis results in a C-weighted time signal. The filter used fulfills Type 0 requirements of standard IEC651 and equivalent. Overall Level - This analysis results in a short Leqs time history of the time signal. Frequency (Lin, A, B, C) and time (Leq, Peak, Fast, etc..) weightings can be applied. Specific Loudness - This analysis results in a Bark band specific loudness, with time history capability (specific loudness multispectrum), a time step <= 50 ms is required for later psychoacoustic criteria computation. The results is e...