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Spectral Filter Application Example #1
You have a Forensics Audio file that is extremely muffled, meaning that its intelligibility is extremely poor because of a lack of the sibilant sounds due to significant high frequency loss. To improve the intelligibility of this file, place the Spectral Filter into Spectral Inverse Mode and check the Auto Sample checkbox. Choose the Auto EQ, Normalize to White Noise or the Auto EQ, Normalize to Human Voice preset. Preview the file. If the sound is improved to your satisfaction, then “Run” the Filter. If the improvement is not adequate, experiment with some of the other Auto EQ based factory presets until you find the best one for your purposes.
Spectral Filter Application Example #2
You have a recording of a male and a female chatting with one another in an automobile. The recorder microphone is closest to the female and it is very hard to discern the male end of the discussion. The background noise is due to the high speed at which the automobile is traveling. However, there is one small sector of the recording where the car was stopped at a traffic light and both the male and female ends of the discussion are clear and discernable. To improve the clarity of the male voice during the times at which the car is traveling at high speeds, place the Spectral Filter in Spectral Copy mode. Highlight the male voice (only) at the point where the car was stopped at the traffic light and then click on the Sample Spectrum button in order to obtain a sound-print. Then, using this sample, “Preview” or “Run” the Spectral filter in the areas of the recording during which the male voice was not discernable.
Spectral Filter Application Example #3
You have a cockpit voice recording containing a lot of airplane noise. You desire to listen to hear if the flaps-down switch has been flipped at a certain point in time, but at the point in time in question, all you hear is random noise. You desire to enhance the playback of the recording to hear whether or not the sound of that switch being flipped by the pilot of the aircraft is present on the recording. You can go to a flight simulator of the aircraft in question and record the sound of that switch being flipped with a quiet ambient noise environment. Bring up that sound file and highlight the actual sound of the switch being flipped. Next place the Spectral Filter into Spectral Copy mode of operation and then click on the Sample Spectrum button. Bring up the cockpit voice recording .wav file and “Preview” it around the time period in question. This action should provide more gain of the sound-print spectrum occupied by the flipping of the switch potentially making it more audible. Obviously, you can’t prove the negative by this technique, but if the switch is heard, you can demonstrate that something took place at the point in time in question. Of course, that positive result may represent the wrong switch being thrown, but that is beyond the scope of this application example.
Spectral Filter Application Example #4
You have recordings of an old television variety show from the 1950s (created before the advent of video tape recording). Your job is to assemble a new digital edit of this television series. The dialog and music are both recorded on a cine optical track. However, a much higher quality copy of the musical portion of the show exists on magnetic tape (sans dialog). In the editing process, you need to use the optical track to assemble the edit, but you insert the magnetic track for the musical portion of the job because of its higher sonic quality. However, you observe that there is an unnatural transition between the dialog (optical) track and the musical (magnetic) track. You can create more natural transitions between the dialog and the musical interludes by employing the Spectral Difference mode of the Spectral Filter to the project. Use the Magnetic track as the “Source” Track and then apply that to the Target optical portions of the final edit using the Spectral Difference feature.
Spectral Filter Application Example #5
You have transferred an old acoustical recording of a famous opera singer to your hard drive. You have removed the noise, but the recording sounds honky, hollow, resonant and unnatural. But, you have a more modern recording of this singer created during the electrical recording period of time. You can use the Spectral Difference feature to create a more natural sounding result. Just use the more modern recording as the Source .wav file and then apply it to the acoustical recording as the Target.
You have a Forensics Audio file that is extremely muffled, meaning that its intelligibility is extremely poor because of a lack of the sibilant sounds due to significant high frequency loss. To improve the intelligibility of this file, place the Spectral Filter into Spectral Inverse Mode and check the Auto Sample checkbox. Choose the Auto EQ, Normalize to White Noise or the Auto EQ, Normalize to Human Voice preset. Preview the file. If the sound is improved to your satisfaction, then “Run” the Filter. If the improvement is not adequate, experiment with some of the other Auto EQ based factory presets until you find the best one for your purposes.
Spectral Filter Application Example #2
You have a recording of a male and a female chatting with one another in an automobile. The recorder microphone is closest to the female and it is very hard to discern the male end of the discussion. The background noise is due to the high speed at which the automobile is traveling. However, there is one small sector of the recording where the car was stopped at a traffic light and both the male and female ends of the discussion are clear and discernable. To improve the clarity of the male voice during the times at which the car is traveling at high speeds, place the Spectral Filter in Spectral Copy mode. Highlight the male voice (only) at the point where the car was stopped at the traffic light and then click on the Sample Spectrum button in order to obtain a sound-print. Then, using this sample, “Preview” or “Run” the Spectral filter in the areas of the recording during which the male voice was not discernable.
Spectral Filter Application Example #3
You have a cockpit voice recording containing a lot of airplane noise. You desire to listen to hear if the flaps-down switch has been flipped at a certain point in time, but at the point in time in question, all you hear is random noise. You desire to enhance the playback of the recording to hear whether or not the sound of that switch being flipped by the pilot of the aircraft is present on the recording. You can go to a flight simulator of the aircraft in question and record the sound of that switch being flipped with a quiet ambient noise environment. Bring up that sound file and highlight the actual sound of the switch being flipped. Next place the Spectral Filter into Spectral Copy mode of operation and then click on the Sample Spectrum button. Bring up the cockpit voice recording .wav file and “Preview” it around the time period in question. This action should provide more gain of the sound-print spectrum occupied by the flipping of the switch potentially making it more audible. Obviously, you can’t prove the negative by this technique, but if the switch is heard, you can demonstrate that something took place at the point in time in question. Of course, that positive result may represent the wrong switch being thrown, but that is beyond the scope of this application example.
Spectral Filter Application Example #4
You have recordings of an old television variety show from the 1950s (created before the advent of video tape recording). Your job is to assemble a new digital edit of this television series. The dialog and music are both recorded on a cine optical track. However, a much higher quality copy of the musical portion of the show exists on magnetic tape (sans dialog). In the editing process, you need to use the optical track to assemble the edit, but you insert the magnetic track for the musical portion of the job because of its higher sonic quality. However, you observe that there is an unnatural transition between the dialog (optical) track and the musical (magnetic) track. You can create more natural transitions between the dialog and the musical interludes by employing the Spectral Difference mode of the Spectral Filter to the project. Use the Magnetic track as the “Source” Track and then apply that to the Target optical portions of the final edit using the Spectral Difference feature.
Spectral Filter Application Example #5
You have transferred an old acoustical recording of a famous opera singer to your hard drive. You have removed the noise, but the recording sounds honky, hollow, resonant and unnatural. But, you have a more modern recording of this singer created during the electrical recording period of time. You can use the Spectral Difference feature to create a more natural sounding result. Just use the more modern recording as the Source .wav file and then apply it to the acoustical recording as the Target.