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This filter is very easy to use and often will provide a good solution to your noise problem, even if not 100 percent optimal. It combines a dual question wizard scheme coupled with a high degree of automation, adaptive filtering techniques and 170 pre-programmed filter solutions. In some situations, the EZ Filter process will help you to hone-in on the best solution to a Forensics Audio problem. It will present you with a few filters to choose from after you answer a few questions. By previewing your file and comparing the alternative filters presented, you can then choose the best filter for the job at hand.
A graphical display shows you the amplitude vs. frequency of the input signal to the filter. The black line shows the user modified output response on the output side of the EZ Forensics filter. The adjustable blue inflection point (square dot which is adjustable with your mouse) is the user interface for adjusting the output response of the system after the best filter has been selected.
The EZ Forensics Filter
The basic process for using the EZ Forensics Filter is as follows:
1. Answer the First Question found in “Step 1: Select File Type”. Click on the “File Type” button and a “Recording Type” Dialog Box will appear. Choose (by left mouse clicking) between the alternatives based on the nature of your audio source including:
2. Click on “Next” in the “Recording Type” Dialog Box and then
answer the second question presented in the “Recording Problems” Dialog Box. You can choose between:
3. Under “Step 2:” you will notice that a number of filters are presented to you. Choose the best one by “Previewing” each one and decide on which one does the best job.
4. You can “tweak” the response of the system by left-moussing the blue inflection point on the graphic display to provide emphasis or attenuation anywhere on the frequency spectrum that you desire. Moving the mouse horizontally changes its frequency while moving the mouse vertically amplifies or attenuates the signal at that frequency. You can also adjust the “Output Level” with the slider control having the same name. Be sure that you do not “clip” the output to avoid signal distortion. A clipping condition is indicated by the illumination of the red “Clip” virtual LED indicator.
5. If and when you are satisfied with the results, then highlight the file or a portion thereof and click on the “Run Filter” button.
Now, Wasn’t That Easy?
A description of the filter type being used is annunciated just below “File Type” button. If the EZ Forensics Filter did not provide the optimal result, the DC Forensics10 Audio Laboratory provides you with a wide array of alternative filters that you can customize for a specific Forensics Audio application. They can be used individually (one at a time) or in concert with one another via the Diamond Cut Multifilter.
Advanced EZ Forensics Filters
To “Go Advanced” with the EZ Forensics approach, a good place to start is with the following two Multifilter Presets (found under the Multifilter and not under the EZ Forensics Filter):
EZ Forensics_Proto1 (A Time Domain Adaptive Filter Based
Approach)
EZ Forensics_Proto2 (An Adaptive Frequency Domain Filter
based Approach)
These two Multifilter presets provide you with the basic signal path structure used in the EZ Forensics system. But, in the Multifilter, you have complete control over a myriad of parameters which you can customize and tweak to your specific needs. Consider using this approach in the event that the EZ Forensics Filter is not providing the optimal results that you seek.
Note 1: It is important to convert all forensics .wav files (8 kHz, 11.025 kHz and 22.05 kHz) up to a 44.1 kHz sampling rate before using the EZ Forensics Filter. To accomplish this, use the Change Sample Rate feature found under the Edit menu.
Note 2: The best results will be realized by applying the “Normalize Gain Scaling” feature (found under the CD Prep Menu) to – 6 dB before running the EZ Forensics Filter.
A graphical display shows you the amplitude vs. frequency of the input signal to the filter. The black line shows the user modified output response on the output side of the EZ Forensics filter. The adjustable blue inflection point (square dot which is adjustable with your mouse) is the user interface for adjusting the output response of the system after the best filter has been selected.
The EZ Forensics Filter
The basic process for using the EZ Forensics Filter is as follows:
1. Answer the First Question found in “Step 1: Select File Type”. Click on the “File Type” button and a “Recording Type” Dialog Box will appear. Choose (by left mouse clicking) between the alternatives based on the nature of your audio source including:
- Single Talker
- Multiple Talkers
- Telephone or 2-Way Radio Communications
- Background Sounds
- Binaural (2 Mic) Decoding
2. Click on “Next” in the “Recording Type” Dialog Box and then
answer the second question presented in the “Recording Problems” Dialog Box. You can choose between:
- Something Else Not Listed Here
- Hissy, Sibilant High Frequency Noise
- Low Frequency Rumbling Noise
- Muffled or Muted Sound
- Power Line Hum
- Buzz
- Steady Tones
- Variable or Swept Frequency Tones
3. Under “Step 2:” you will notice that a number of filters are presented to you. Choose the best one by “Previewing” each one and decide on which one does the best job.
4. You can “tweak” the response of the system by left-moussing the blue inflection point on the graphic display to provide emphasis or attenuation anywhere on the frequency spectrum that you desire. Moving the mouse horizontally changes its frequency while moving the mouse vertically amplifies or attenuates the signal at that frequency. You can also adjust the “Output Level” with the slider control having the same name. Be sure that you do not “clip” the output to avoid signal distortion. A clipping condition is indicated by the illumination of the red “Clip” virtual LED indicator.
5. If and when you are satisfied with the results, then highlight the file or a portion thereof and click on the “Run Filter” button.
Now, Wasn’t That Easy?
A description of the filter type being used is annunciated just below “File Type” button. If the EZ Forensics Filter did not provide the optimal result, the DC Forensics10 Audio Laboratory provides you with a wide array of alternative filters that you can customize for a specific Forensics Audio application. They can be used individually (one at a time) or in concert with one another via the Diamond Cut Multifilter.
Advanced EZ Forensics Filters
To “Go Advanced” with the EZ Forensics approach, a good place to start is with the following two Multifilter Presets (found under the Multifilter and not under the EZ Forensics Filter):
EZ Forensics_Proto1 (A Time Domain Adaptive Filter Based
Approach)
EZ Forensics_Proto2 (An Adaptive Frequency Domain Filter
based Approach)
These two Multifilter presets provide you with the basic signal path structure used in the EZ Forensics system. But, in the Multifilter, you have complete control over a myriad of parameters which you can customize and tweak to your specific needs. Consider using this approach in the event that the EZ Forensics Filter is not providing the optimal results that you seek.
Note 1: It is important to convert all forensics .wav files (8 kHz, 11.025 kHz and 22.05 kHz) up to a 44.1 kHz sampling rate before using the EZ Forensics Filter. To accomplish this, use the Change Sample Rate feature found under the Edit menu.
Note 2: The best results will be realized by applying the “Normalize Gain Scaling” feature (found under the CD Prep Menu) to – 6 dB before running the EZ Forensics Filter.