Tweet
Averaging Filter
This filter sounds similar to that of a Low-pass filter, although it is somewhat more effective than a Low-pass filter in reducing not only "Hiss" but also "Crackle" from a sound source. It is most effective on limited bandwidth sources such as old acoustic recordings made before 1925. This filter is also useful for improving the intelligibility of highly garbled voice communications recordings.
The Averaging Filter
This is another filter that has no analog equivalent. Its interface to the operator is similar to the Median Filter, with the difference being that instead of calculating the median value of a sample window to pass into the Destination workspace, the average value of a group of samples is passed through. You select the number of samples on which the average value is calculated with a slider control in its dialog box. The greater the number of samples, the higher the degree of smoothing effect on the waveform. The higher that you set the degree of smoothing, the greater will be the loss in the higher end of the audio frequency spectrum.
The following is a summary of the control parameters and the range of adjustment provided for the Average Filter:
This filter sounds similar to that of a Low-pass filter, although it is somewhat more effective than a Low-pass filter in reducing not only "Hiss" but also "Crackle" from a sound source. It is most effective on limited bandwidth sources such as old acoustic recordings made before 1925. This filter is also useful for improving the intelligibility of highly garbled voice communications recordings.
The Averaging Filter
This is another filter that has no analog equivalent. Its interface to the operator is similar to the Median Filter, with the difference being that instead of calculating the median value of a sample window to pass into the Destination workspace, the average value of a group of samples is passed through. You select the number of samples on which the average value is calculated with a slider control in its dialog box. The greater the number of samples, the higher the degree of smoothing effect on the waveform. The higher that you set the degree of smoothing, the greater will be the loss in the higher end of the audio frequency spectrum.
The following is a summary of the control parameters and the range of adjustment provided for the Average Filter:
- Samples: 2 - 100
- Preview Mode Button: On / Off (The slider control can be adjusted "live" when the preview mode is being used.)
- Bypass Button: Allows you to compare between the filtered and the raw signal.
- Keep Residue: Allows you to hear what the Filter is removing from the raw signal.
- Highlight the portion of your .wav file on which you desire to apply the Average Filter. (You may choose to highlight the entire file or any portion thereof.)
- Click on the “Filter Menu” with the left mouse button.
- Click on "Averaging".
- Choose the number of Samples over which you desire the moving average calculation to be performed. The higher the number of samples chosen, the greater will be the attenuation of the higher frequency portion of the audio spectrum. You can choose any integer value from 2 to 100 samples. The higher the number of samples selected, the longer will be the processing time requirement for the algorithm. This selection is accomplished utilizing the slider control.
- If you desire to hear the results of your filter settings before creating a new "Destination" file, click on "preview."
- You will hear the effect of the averaging over the chosen value of "samples".
- As the filter is running in either preview mode or normal mode (Destination File Mode), you will see a dialog box that indicates the "Percent Done" of the filter algorithm on the selected portion of the Source .wav file. Also, at the top of the Dialog box you will see indicated the "Total samples to process:"
- Keep adjusting the number of samples until you achieve your desired effect.
- When you are satisfied with a setting, you will no longer use the “Preview” mode button.
- Click on “Run”, and the filter will process your source .wav file through the filter algorithm, and create a Destination .wav file containing the output of the filter.
- When this process is complete, you will see the Destination File become highlighted in Yellow, at the same time that the Source File becomes unselected.
- Click on "Close".